Abrogation of G2/M arrest sensitizes curcumin-resistant hepatoma cells to apoptosis

Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Xin Gang Xi Road 135, Guangzhou 510275, PR China.
FEBS Letters (Impact Factor: 3.34). 08/2008; 582(18):2689-95. DOI: 10.1016/j.febslet.2008.06.048
Source: PubMed

ABSTRACT In this study, we showed that curcumin treatment resulted in activation of Chk1-mediated G2 checkpoint, which was associated with the induction of G2/M arrest and the resistance of cancer cells to curcumin-induced apoptosis. Further investigation revealed that inhibition of Chk1 significantly abrogated G2/M arrest and sensitized curcumin-resistant cells to apoptosis via upregulation of Bad and in turn the loss of mitochondrial membrane potential. These results indicate that Chk1-mediated G2/M arrest may serve as a mechanism for curcumin resistance and Chk1 represents a potential target for the reversal of this resistance. Our findings should be helpful for clinical application of curcumin.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies worldwide. The clinical management of HCC remains a substantial challenge. Although surgical resection of tumor tissues seems promising, a high recurrence and/or metastasis rate accounting for disease-related death has led to an urgent need for improved postsurgical preventive/therapeutic clinical intervention. Developing advanced target-therapy agents such as sorafenib appears to be the only effective clinical intervention for patients with HCC to date, but only limited trials have been conducted in this regard. Because of their enhanced preventive/therapeutic effects, traditional Chinese herbal medicine (CHM)-derived compounds are considered suitable agents for HCC treatment. The CHM-derived compounds also possess multilevel, multitarget, and coordinated intervention effects, making them ideal candidates for inhibition of tumor progression and HCC metastasis. This article reviews the anticancer activity of various CHMs with the hope of providing a better understanding of how to best use CHM for HCC treatment.
    Journal of the Chinese Medical Association 10/2014; 78(3). DOI:10.1016/j.jcma.2014.09.003 · 0.89 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Philadelphia chromosome positive (Ph+) acute lymphoblastic leukemia (ALL) cells are insensitive to BCR-ABL tyrosine kinase inhibitor imatinib, the underlying mechanisms remain largely unknown. Here, we showed that imatinib treatment induced significant upregulation of miR-21 and downregulation of PTEN in Ph+ ALL cell line Sup-b15. Transient inhibition of miR-21 resulted in increased apoptosis, PTEN upregulation and AKT dephosphorylation, whereas ectopic overexpression of miR-21 further conferred imatinib resistance. Furthermore, knockdown of PTEN protected the cells from imatinib-induced apoptosis achieved by inhibition of miR-21. Additionally, PI3K inhibitors also notably enhanced the effects of imatinib on Sup-b15 cells and primary Ph+ ALL cells similar to miR-21 inhibitor. Therefore, miR-21 contributes to imatinib resistance in Ph+ ALL cells and antagonizing miR-21 demonstrates therapeutic potential by sensitizing the malignancy to imatinib therapy.
    Biochemical and Biophysical Research Communications 10/2014; 454(3). DOI:10.1016/j.bbrc.2014.10.107 · 2.28 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: Drug resistance remains a major challenge for effective breast cancer chemotherapy. Resveratrol (Res) is a promising candidate for overcoming cancer chemoresistance, but it has low bioavailability due to poor absorption, and ready metabolism limits its application. This study aims to develop a Res-loaded mixed micelle system to be effective on drug resistance of breast cancer cells. Methods: A mixed micelle system made of methoxy poly (ethylene glycol)-b-polycaprolactone (mPEG-PCL) and d-α-Tocopherol polyethylene glycol succinate was prepared and Res was encapsulated to form Res-loaded mixed micelles. Furthermore, the antitumor activity against doxorubicin (Dox)-resistant breast cancer MCF-7/ADR cells was studied and the possible mechanism was elucidated. Results: The mixed micellar formulation increased drug uptake efficiency of Res by Dox-resistant breast cancer MCF-7/ADR cells, and induced higher rates of apoptotic cell death, as assessed by the accumulation of Sub G1 phases of cell cycle, nucleus staining and Annexin-FITC/propidium iodide assay. Moreover, Res-loaded mixed micelles also markedly enhanced Dox-induced cytotoxicity in MCF-7/ADR cells and increased the cellular accumulation of Dox by downregulating the expression of P-glycoprotein (P-gp) and inhibiting the activity thereof. Conclusion: The cumulative evidence indicates that Res-loaded mixed micelles hold significant promise for the treatment of drug-resistant breast cancer.
    Expert Opinion on Drug Delivery 11/2014; 12(3):1-13. DOI:10.1517/17425247.2014.951634 · 4.12 Impact Factor


1 Download
Available from