Advances in Nanoplatforms for Immunotherapy Applications Targeting the Tumor Microenvironment.

Cancer immunotherapy is a treatment method that activates or enhances the autoimmune response of the body to fight tumor growth and metastasis, has fewer toxic side effects and a longer-lasting efficacy than radiotherapy and chemotherapy, and has become an important means for the clinical treatment of cancer. However, clinical results from immunotherapy have shown that most patients lack responsiveness to immunotherapy and cannot benefit from this treatment strategy. The tumor microenvironment (TME) plays a critical role in the response to immunotherapy. The TME typically prevents effective lymphocyte activation, reducing their infiltration, and inhibiting the infiltration of effector T cells. According to the characteristic differences between the TME and normal tissues, various nanoplatforms with TME targeting and regulation properties have been developed for more precise regulation of the TME and have the ability to codeliver a variety of active pharmaceutical ingredients, thereby reducing systemic toxicity and improving the therapeutic effect of antitumor. In addition, the precise structural design of the nanoplatform can integrate specific functional motifs, such as surface-targeted ligands, degradable backbones, and TME stimulus-responsive components, into nanomedicines, thereby reshaping the tumor microenvironment, improving the body's immunosuppressive state, and enhancing the permeability of drugs in tumor tissues, in order to achieve controlled and stimulus-triggered release of load cargo. In this review, the physiological characteristics of the TME and the latest research regarding the application of TME-regulated nanoplatforms in improving antitumor immunotherapy will be described. Furthermore, the existing problems and further applications perspectives of TME-regulated platforms for cancer immunotherapy will also be discussed.

Genipin Inhibits LPS-Induced Inflammatory Response in BV2 Microglial Cells.

Genipin, an aglycon of geniposide, has been reported to have anti-inflammatory effect. However, the anti-inflammatory activity of genipin on LPS-stimulated BV2 microglial cells has not been reported. In this study, we investigated the molecular mechanisms responsible for the anti-inflammatory activity of genipin both in vivo and in vitro. The levels of TNF-α, IL-1ß, NO and PGE2 were detected by ELISA. The expression of Nrf2, HO-1, and NF-κB were detected by western blot analysis. In vivo, genipin significantly attenuated LPS-induced memory deficit in the Morris water maze and passive avoidance tasks. Genipin also inhibited LPS-induced TNF-α and IL-1ß expression in brain tissues. In vitro, our results showed that genipin inhibited LPS-induced TNF-α, IL-1ß, NO and PGE2 production in a concentration-dependent manner. Genipin also suppressed LPS-induced NF-κB activation. In addition, the expression of Nrf2 and HO-1 were up-regulated by treatment of genipin. Furthermore, the inhibition of genipin on inflammatory mediator production was attenuated by transfection with Nrf2 siRNA. In conclusion, genipin inhibited LPS-induced inflammatory response by activating Nrf2 signaling pathway in BV2 microglia.

Up-regulation of long non-coding HOTTIP functions as an oncogene by regulating HOXA13 in non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is the major cause of cancer death worldwide. Increasing evidences show that long non coding RNAs (lncRNAs) are widely involved in the development and progression of NSCLC. The lncRNA HOTTIP has been identified as an oncogene in several human cancers, but its role in NSCLC remains unknown. The present study was to determine the expression and function of HOTTIP in NSCLC. Quantitative real-time PCR was used to detect the expressions of HOTTIP in 53 paired NSCLC tissues and cell lines. Furthermore, RNA interference (RNAi) and over-expression approaches were used to investigate the biological function of HOTTIP in lung cancer cell line. The impacts of HOTTIP on cell migration, proliferation and apoptosis were analyzed using wound scratch assay, MTT and flow cytometry, respectively. The results revealed that the HOTTIP expression was significantly up-regulated in NSCLC tissues and cells when compared with corresponding adjacent normal tissues and normal bronchial epithelial cells (p<0.05). Furthermore, knock-down of HOTTIP significantly inhibited cell proliferation, migration and induced cell apoptosis in vitro, while over-expression of HOTTIP led to the opposite effects. In addition, we identified HOTTIP as a transcriptional regulator of HOXA13 in lung cancer cell. Ectopic expression of HOTTIP suppressed the endogenous level of HOXA13, while knock-down of HOTTIP increased HOXA13 expression. Knock-down of HOXA13 by RNA interference (siHOXA13) revealed that HOTTIP promoted lung cell proliferation, migration, and inhibited apoptosis, at least partly by regulating HOXA13. The present study is the first to identify that HOTTIP functions as an oncogene by regulating HOXA13 in NSCLC, which may represent a new biomarker and a potential therapeutic target for NSCLC intervention.

Hsa-miR-495 acts as a tumor suppressor gene in glioma via the negative regulation of MYB.

MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression at the post-transcriptional level. Previous studies have reported that there are causative links between the abnormal regulation of miRNAs and cancer development. Hsa­miR­495 has previously been demonstrated to be downregulated, and to function as a tumor suppressor, in numerous types of human cancer. However, the function and molecular mechanism of hsa­miR­495 in glioma remains unclear. In the current study, the expression and effects of hsa­miR­495 on glioma were evaluated. It was identified that the expression levels of hsa-miR-495 were downregulated in glioma tissues and cell lines. Furthermore, restoration of hsa-miR-495 inhibited glioma cell proliferation and invasion in vitro. Notably, a luciferase reporter assay revealed that hsa­miR­495 was able to directly target v­myb avian myeloblastosis viral oncogene homolog (MYB) in glioma cells. In addition, an RNA interference assay indicated that MYB knockdown inhibited glioma cell proliferation and invasion in vitro. In conclusion, the results of the present study suggested that hsa­miR­495 may act as a tumor suppressor gene in glioma by directly inhibiting MYB expression, which may provide a novel therapeutic strategy for the treatment of glioma.

MicroRNA-300 inhibited glioblastoma progression through ROCK1.

Glioblastoma is a common type of brain aggressive tumors and has a poor prognosis. MicroRNAs (miRNAs) are a class of small, endogenous and non-coding RNAs that play crucial roles in cell proliferation, survival and invasion. Deregulated expression of miR-300 has been studied in a lot of cancers. However, the role of miR-300 in glioblastoma is still unknown. In this study, we demonstrated that miR-300 expression was downregulated in glioblastoma tissues compared with the normal tissues. Lower expression level of miR-300 was observed in thirty cases (75 %, 30/40) of glioblastoma samples compared with the normal samples. Moreover, the overall survival of glioblastoma patients with lower miR-300 expression level was shorter than those with higher miR-300 expression level. In addition, miR-300 expression was also downregulated in glioblastoma cell lines. Overexpression of miR-300 inhibited cell proliferation, cell cycle and invasion in glioblastoma cell line U87 and U251. Moreover, we identified ROCK1 as a direct target of miR-300 in U87 and U251 cells. Overexpression of ROCK1 partially rescued the miR-300-mediated cell growth. ROCK1 expression levels in glioblastoma tissues were higher than that in normal tissues. ROCK1 expression levels were higher in thirty-one cases of glioblastoma samples than their normal samples. Furthermore, the expression level ROCK1 was inversely correlated with the expression level of miR-300. Importantly, overexpression of miR-300 suppressed glioblastoma progression in an established xenograft model. In conclusion, we revealed that miR-300 might act as a tumor suppressor gene through inhibiting ROCK1 in glioblastoma.