Cancer Stem Cell Biomarkers: Critical Roles, Challenges, Clinical Application, and Perspectives in Cancer Therapy

Progress in cancer stem cells (CSCs) has opened up a new window to develop better cancer treatment methods. Several preclinical and clinical trial studies use CSCs targeting via surface markers method and inhibiting stem cell pathway to eradicate cancer. Investigations disclose that CSCs are more resistant to chemo- and radiotherapy than non-CSCs. If CSCs are destroyed with treatment, cancer cells will be deleted. This feature is mainly related to their surface biomarkers and thus, detection and Isolation of CSCs are so critical. This study introduced the most important cell surface markers of CSCs such as CD133, CD44, CD24, and CD90 and evaluated these biomarkers. Today, more than 60 ongoing trials have been evaluated, few of which are used in clinical trials to determine if a new drug is effective. Then, we discuss the challenges of several therapies.

Nanocurcumin-Mediated Down-Regulation of Telomerase Via Stimulating TGFβ1 Signaling Pathway in Hepatocellular Carcinoma Cells

Background

Curcumin, extracted from turmeric, represents enormous potential to serve as an anticancer agent. Telomerase is viewed as a prominent molecular target of curcumin, and Transforming growth factor-β1 (TGFβ1) has proven to be a major inhibitory signaling pathway for telomerase activity. In the current study, we aimed to explore suppressive effects of nanocurcumin on telomerase expression through TGFβ1 pathway in a hepatocellular carcinoma cell line (Huh7).

Methods

MTT assay was used to determine the effect of nonocurcumin on viability of Huh7 cells. RT-PCR was used to analyze the gene expression patterns.

Results

MTT assay revealed that nanocurcumin acts in a dose- and time-dependent manner to diminish the cell viability. RT-PCR analysis indicated that nanocurcumin results in augmentation of TGFβ1 72 hours post treatment and leads to the reduction of telomerase expression 48 and 72 hours post exposure. Also, up-regulation of Smad3 and E2F1 and down-regulation of Smad7 confirmed the effect of nanocurcumin on intermediate components of TGFβ1 pathway. Furthermore, transfection of the proximal promoter of telomerase triggered a significant reduction in luciferase activity.

Conclusion

The data from the present study lead us to develop a deeper understanding of the mechanisms underlying nanocurcumin-mediated regulation of telomerase expression, thereby presenting a new perspective to the landscape of using nanocurcumin as a cancer-oriented therapeutic agent.

Nano Packaged Tamoxifen and Curcumin; Effective Formulation against Sensitive and Resistant MCF-7 Cells

Tamoxifen is routinely used for treatment of Estrogen-positive breast carcinoma. Approximately, 50% of patients with metastatic cancer will develop resistance to Tamoxifen. In this research, Tamoxifen was combined with the anti-cancer compound Curcumin. Diblocknanopolymer was used to package the new formulation of Curcumin and Tamoxifen. Anti-cancer efficacy of the obtained compound was evaluated in Tamoxifen-sensitive (TS). MCF-7, Tamoxifen-resistant (TR) MCF-7 cancer cells and Fibroblast cells. MTT assay was used to evaluate anti-proliferation and toxicity. Flow cytometry and Annexin-V-FLUOS were used to assay anti-proliferation and induction of apoptosis respectively. Our results indicate that the obtained nano-compound is less toxic to normal cells compared to Tamoxifen alone, and has higher anti-proliferation and pro-apoptotic activity on TS-MCF-7 and TR-MCF-7. The nanopolymer reduces the Tamoxifen toxicity in normal cells and counters the developed resistance to the drug in cancer cells.

Preparation and Evaluation of Rifampicin and Co-trimoxazole-loaded Nanocarrier against Brucella melitensis Infection

Background:

Brucellosis or Malta fever is a contagious infection common between human and domestic animals. Many antibiotics are used for brucellosis treatment, but they are not efficient and put heavy burden on society. Co-trimoxazole and rifampicin are two candidates for brucellosis treatment. In this study, we aimed to enhance the efficacy of these antibiotics using designed nanoparticles.

Methods:

Different concentrations of co-trimoxazole and rifampicin were used for loading onto a nanostructure of synthesized monomethoxy poly(ethylene glycol)-oleate (mPEG-OA). The solubility, cytotoxicity, and efficacy of these nano-packed antibiotics on Brucella-infected murine phagocytic cells were examined, as compared with free antibiotics. Then the release nanoparticles was increased approximately 3.5 and 1.5fold, respectively, which is considerable in comparison with free insoluble ones.

Results:

Despite acceptable loading percentage, the application of co-trimoxazole-loaded nanoparticle on Brucella-infected J774A.1 murine macrophage-like cells did not lead to reduction in the number of bacteria; however, the efficacy of rifampicin on Brucella-infected murine phagocytic cells enhanced.

Conclusion:

In the current study, the efficacy of rifampicin on reducing the number of Brucella melitensis increased by the novel synthesized nanostructure. In contrast, since co-trimoxazole efficacy did not enhance by loading onto nanoparticles, the co-trimoxazole inefficiency is most likely not due to its low penetration or insolubility, and probably there are other factors that remain to be clarified in the future investigations.