Nanoparticles and targeted drug delivery in cancer therapy.

Surgery, chemotherapy, radiotherapy, and hormone therapy are the main common anti-tumor therapeutic approaches. However, the non-specific targeting of cancer cells has made these approaches non-effective in the significant number of patients. Non-specific targeting of malignant cells also makes indispensable the application of the higher doses of drugs to reach the tumor region. Therefore, there are two main barriers in the way to reach the tumor area with maximum efficacy. The first, inhibition of drug delivery to healthy non-cancer cells and the second, the direct conduction of drugs into tumor site. Nanoparticles (NPs) are the new identified tools by which we can deliver drugs into tumor cells with minimum drug leakage into normal cells. Conjugation of NPs with ligands of cancer specific tumor biomarkers is a potent therapeutic approach to treat cancer diseases with the high efficacy. It has been shown that conjugation of nanocarriers with molecules such as antibodies and their variable fragments, peptides, nucleic aptamers, vitamins, and carbohydrates can lead to effective targeted drug delivery to cancer cells and thereby cancer attenuation. In this review, we will discuss on the efficacy of the different targeting approaches used for targeted drug delivery to malignant cells by NPs.

Adipose Derived Stem Cells Exert Immunomodulatory Effects on Natural Killer Cells in Breast Cancer.

OBJECTIVE: Adipose derived stem cells (ASCs), as one of the important stromal cells in the tumor microenvironment, are determined with immunomodulatory effects. The principle aim of this study was to evaluate the immunosuppressive effects of ASCs on natural killer (NK) cells. MATERIALS AND METHODS: In this experimental study, we assessed the expressions of indolamine 2, 3-dioxygenase (IDO1), IDO2 and human leukocyte antigen-G5 (HLA-G5) in ASCs isolated from breast cancer patients with different stages as well as normal individuals, using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Immunomodulatory effects of ASCs on the expression of CD16, CD56, CD69, NKG2D, NKp30, NKG2A and NKp44 was also assessed in peripheral blood lymphocytes (PBLs) by flow-cytometry. RESULTS: Our result showed that IDO1, IDO2 and HLA-G5 had higher mRNA expressions in ASCs isolated from breast cancer patients than those from normal individuals (P>0.05). mRNA expression of these molecules were higher in ASCs isolated from breast cancer patients with stage III tumors than those with stage II. The indirect culture of ASCs isolated from breast cancer patients and normal individuals with activated PBLs significantly reduced NKG2D+ and CD69+ NK cells (P<0.05). CONCLUSION: Results of the present study suggest more evidences for the immunosuppression of ASCs on NK cells, providing conditions in favor of tumor immune evasion.

Folate-conjugated nanoparticles as a potent therapeutic approach in targeted cancer therapy.

The selective and efficient drug delivery to tumor cells can remarkably improve different cancer therapeutic approaches. There are several nanoparticles (NPs) which can act as a potent drug carrier for cancer therapy. However, the specific drug delivery to cancer cells is an important issue which should be considered before designing new NPs for in vivo application. It has been shown that cancer cells over-express folate receptor (FR) in order to improve their growth. As normal cells express a significantly lower levels of FR compared to tumor cells, it seems that folate molecules can be used as potent targeting moieties in different nanocarrier-based therapeutic approaches. Moreover, there is evidence which implies folate-conjugated NPs can selectively deliver anti-tumor drugs into cancer cells both in vitro and in vivo. In this review, we will discuss about the efficiency of different folate-conjugated NPs in cancer therapy.