Therapeutic effect of the treatment for colorectal cancer with adenoviral vectors mediated estrogen receptor β gene therapy combined with thermotherapy

Progress in the Development of Chitosan-Based Biomaterials for Tissue Engineering and Regenerative Medicine

Over the last few decades, chitosan has become a good candidate for tissue engineering applications. Derived from chitin, chitosan is a unique natural polysaccharide with outstanding properties in line with excellent biodegradability, biocompatibility, and antimicrobial activity. Due to the presence of free amine groups in its backbone chain, chitosan could be further chemically modified to possess additional functional properties useful for the development of different biomaterials in regenerative medicine. In the current review, we will highlight the progress made in the development of chitosan-containing bioscaffolds, such as gels, sponges, films, and fibers, and their possible applications in tissue repair and regeneration, as well as the use of chitosan as a component for drug delivery applications.

Evaluation of the Synergism Mechanism of Tamoxifen and Docetaxel by Nanoparticles

BACKGROUND

Our previous studies have shown that Docetaxel (DTX) and Tamoxifen (TMX) loaded nanoparticles(Co-NPs) could exhibit a synergistic effect on estrogen receptor positive cell lines. In the current study，we have studied the synergistic effect of Co-NPs and underlying possible molecular mechanism.

METHODS

Cell apoptosis assay, pharmacokinetic experiment and immunohistochemistry experiment were used to explore the synergistic effect and underlying possible mechanism in vitro and in vivo.

RESULTS

Cell apoptosis assay revealed that Co-NPs could mediate cell sensitization to a cytotoxic agent, resulting in remarkable cell apoptosis. In addition, pharmacokinetic experiment research showed that Co-NPs have longer circulation time in vivo, which could prolong the treatment time of the chemotherapeutic drugs. Immunohistochemistry experiment revealed that the Co-NPs could downregulate the expression of P-gp level to reduce the drugs' efflux.

CONCLUSION

The possible mechanism of the synergistic effect of DTX and TMX by Co-NPs was attributed to the longer in vivo circulation time, significantly increased rate of cell apoptosis and downregulated expression of P-gp level to the tumor cells.

Synthesis and biological evaluation of novel 5-chloro-N-(4-sulfamoylbenzyl) salicylamide derivatives as tubulin polymerization inhibitors

A novel series of sulfonamide derivatives, coupled with a salicylamide scaffold, was designed and synthesized. The structures of the synthesized compounds were established using 1H NMR, 13C NMR and high-resolution mass spectroscopy. The synthesized compounds were tested in vitro against five types of human cell lines. Two were breast adenocarcinoma, including the hormone-dependent MCF-7 and the hormone-independent MDA-MB-231. The others were the colorectal adenocarcinoma Caco-2, the carcinoma HCT-116 and the immortalized retinal-pigmented epithelium, hTERT-RPE1. Nine sulfonamides were able to inhibit the growth of the four tested cancer cells. Compound 33 was the most active against the selected colon cancer (Caco-2 and HCT-116) subtypes, while compound 24 showed the best efficacy against the examined breast cancer (MCF-7 and MDA-MB-231) cells. The selectivity index introduced compounds 24 and 33 as having the best selectivity among the breast and colon subtypes, respectively. In vitro tubulin polymerization experiments and flow cytometric assays showed that compounds 24 and 33 led to cell cycle arrest at the G2/M phase in a dose-dependent manner by effectively inhibiting tubulin polymerization. Furthermore, the results of the molecular docking studies indicate that this class of compounds can bind to the colchicine-binding site of tubulin.

The reversion of anti-cancer drug antagonism of tamoxifen and docetaxel by the hyaluronic acid-decorated polymeric nanoparticles

Docetaxel (DTX) and tamoxifen (TMX) are first-line drugs used to treat breast cancer. However when used in combination, they produce antagonism because of their differential metabolic pathways. In order to prevent this antagonism, an amphiphilic copolymer, cholesterol modified hyaruronic acid (HA-CHOL), was synthesized for investigating the co-delivery of TMX and DTX. In vitro drug release experiment of the Co-encapsulated (encapsulated DTX+TMX) nanoparticles (Co-NPs) revealed that NPs with unique release mechanism can markedly reduce the release of these drugs in the circulatory system. However, when reaching in cell, TMX can release rapidly to prevent DTX from coming into contact with metabolizing enzymes. In vitro cytotoxicity experiment revealed that the Co-NPs exhibited a significant synergistic effect for inhibiting the proliferation of the cancer cell lines A549, MCF7 and S180. NPs carrying Coumarin-6(Cou6) exhibited increased cellular uptake compared with Cou6 solution at similar drug concentrations. As an in vivo treatment of xenograft tumors involving 180 cells, the Co-NPs displayed a clear tumor-inhibiting effect. This led us to conclude that the reversion of drug antagonism by NPs was attributed to the increased stability of the nanoparticles in the blood circulation, the efficient cellular uptake, the hierarchical drug metabolism in the tumor and the good and orderly delivery of the drugs to the tumor tissue.

Estrogen receptor beta as target for colorectal cancer prevention

Colorectal cancer (CRC) is a leading cause of death in the United States. Despite its slow development and the capacity for early diagnosis, current preventive approaches are not sufficient. However, a role for estrogen has been demonstrated in multiple epidemiologic studies, which may benefit CRC prevention. A large body of evidence from preclinical studies indicates that expression of the estrogen receptor beta (ERβ/ESR2) demonstrates an inverse relationship with the presence of colorectal polyps and stage of tumors, and can mediate a protective response. Natural compounds, including phytoestrogens, or synthetic ERβ selective agonists, can activate or upregulate ERβ in the colon and promote apoptosis in preclinical models and in clinical experience. Importantly, this activity has been associated with a reduction in polyp formation and, in rodent models of CRC, has been shown to lower incidence of colon adenocarcinoma. Collectively, these findings indicate that targeted activation of ERβ may represent a novel clinical approach for management of colorectal adenomatous polyps and prevention of colorectal carcinoma in patients at risk for this condition. In this review, we discuss the potential of new chemopreventive or dietary approaches based on estrogen signaling.

Enhancement of aqueous stability and fluorescence brightness of indocyanine green using small calix[4]arene micelles for near-infrared fluorescence imaging

Incorporation of ICG into calix[4]arene micelles improves its aqueous stability and fluorescence brightness.

Pterostilbine, an active component of blueberries, sensitizes colon cancer cells to 5-fluorouracil cytotoxicity

Although colorectal cancer (CRC) treatment with 5-fluorouracil (5-FU) is the first line of therapy for this debilitating disease, treatment effectiveness is often hampered by the development of drug resistance and toxicity at high doses. ER-β can play an important role in CRC development and possibly in its response to therapy. Pterostilbene (PT) possesses antioxidant and anticancer effects that are mediated by ER-β. In the current study, we test the hypothesis that PT sensitizes colon cancer cells to 5-FU and we examine the underlying mechanism(s) by which PT exerts its cytotoxic effects in CRC cells. Our data indicate that PT exhibited a more potent cytotoxic effect in Caco-2 compared to HCT-116 cells. PT/5-FU co-treatment was more effective in Caco-2 cells. Our data indicate that ER-β is expressed at higher levels in Caco-2 cells and its levels are further boosted with PT treatment. PT significantly suppressed Akt and ERK phosphorylations, and enhanced FOXO-1 and p27^kip1 levels in Caco-2 cells. PT also induced a significant increase in Caco-2 cells at pre-G phase coupled with increased Bax/Bcl-2 ratio and PARP cleavage. These results provide a rationale for novel combination treatment strategies, especially for patients with 5-FU-resistant tumors expressing ER-β protein.

Estrogen receptors and their implications in colorectal carcinogenesis

Upon binding their cognate receptors, ERα (ESR1) and ERβ (ESR2), estrogens activate intracellular signaling cascades that have important consequences for cellular behavior. Historically linked to carcinogenesis in reproductive organs, estrogens have also been implicated in the pathogenesis of different cancer types of non-reproductive tissues including the colon. ERβ is the predominant estrogen receptor expressed in both normal and malignant colonic epithelium. However, during colon cancer progression, ERβ expression is lost, suggesting that estrogen signaling may play a role in disease progression. Estrogens may in fact exert an anti-tumor effect through selective activation of pro-apoptotic signaling mediated by ERβ, inhibition of inflammatory signals and modulation of the tumor microenvironment. In this review, we analyze the estrogen pathway as a possible therapeutic avenue in colorectal cancer, we report the most recent experimental evidence to explain the cellular and molecular mechanisms of estrogen-mediated protection against colorectal tumorigenesis, and we discuss future challenges and potential avenues for targeted therapy.