Gnetum montanum extract induces apoptosis by inhibiting the activation of AKT in SW480 human colon cancer cells.

CONTEXT: Gnetum montanum Markgr. (Gnetaceae) is used to treat rheumatic arthralgia and bruises in the clinic. OBJECTIVE: To exam the activity and mechanism of G. montanum extract (GME) against colon cancer cells SW480. MATERIALS AND METHODS: The anti-proliferative activity of GME (0-120 µg/mL) on SW480 cells was determined using MTS assay at 24, 48, and 72 h. The in vitro activity of GME (0-120 µg/mL) on SW480 cells was investigated using flow cytometry and western blotting analysis. The in vivo activity of GME was evaluated using xenograft tumour model of zebrafish and nude mice. The chemical composition of GME was detected by using HPLC-MS/MS. RESULTS: The IC50 value SW480 cells viability by GME were 126.50, 78.25, and 50.77 µg/mL, respectively, for 24, 48, and 72 h. The experiments showed that apoptotic cells and G2/M phase cells increased from 20.81 to 61.53% (p < 0.01) and 25.76 to 34.93% with 120 µg/mL GME, respectively. GME also down-regulated the protein expression of P-AKT, P-GSK-3ß, P-PDK1, P-c-Raf, caspase-3, and Bcl-2, and up-regulated the expression cleaved caspase-3, cleaved PARP, and Bax. In vivo study found that GME can significantly inhibit the growth and migration of SW480 cells in xenograft zebrafish. GME reduced the nude mice tumour weight to approximately 32.19% at 28 mg/kg/day and to 53.17% (p < 0.01) at 56 mg/kg/day. Forty-two compounds were identified from the GME. DISCUSSION AND CONCLUSIONS: GME has a significant antitumor effect on colon cancer cells SW480, and it has the potential to be developed as an anticancer agent.

Engineered Polymer Nanoplatforms for Targeted Tumor Cells and Controlled Release Cargos to Enhance Cancer Treatment.

Cancer is composed of a series of uncontrollable cells, which finally form tumors to negatively impact the functions of the body and induce other serious diseases, even leading to death. During the last decades, scientists have devoted great efforts to study cancer; however, there are no effective diagnoses and treatments. Nanomaterials have attracted great attention in the biomedical field in recent years, which are widely used as optical imaging probes and delivery systems for cancer therapy. Among the numerous nanomaterials, polymeric nanoparticles occupy a prominent position because of their tunable micro-size, multifunctional surface, prominent biocompatibility and high drug-carrying capacity. These significant advantages of polymeric nanomaterials have significance over the traditional nanomaterials and have become a potential therapy for cancer. In this review, we focus on the applications of polymeric nanoparticles in cancer theranostics, especially as the drug delivery systems for cancer treatment. This review provides an overview on the advancement of synthesis, application of polymeric nanoparticles- based drug delivery systems and highlights the evaluation for cancer therapy.

CTLA-4 immunotherapy exposes differences in immune response along with different tumor progression in colorectal cancer.

Tumor growth is accompanied by a changing tumor microenvironment and mutations that increase the resistance to therapy. Here, we used syngeneic models to evaluate the drug response of tumors of the same type of different sizes. We used the in vivo efficacy and Ki-67 immunohistochemistry (IHC) assay to assess the difference in responses in response to treatment with the same concentration of anti-CTLA-4. Flow cytometry analysis revealed changes in the immune subpopulations changes the spleen, peripheral blood, lymph node, and tumor tissue across different tumor growth phases. For example, naive CD4+T, CD4+TCM, CD8+TEM, T, B, Treg, CD8+TCM exhibited different percentages depending on the specific immune organ. To further expose the changes in the immune microenvironment, the level of expression of PD-1 and CTLA-4 showed statistically significant difference in related subsets for each four immune tissues in different tumor sizes. In addition, the ratios of CD4 + Teff/ CD4 + Treg and CD8 + T/Treg in corresponding immune tissue were also associated with statistically significant differences alongside tumor growth in different animal models. These results reveal the ongoing changes in the immune microenvironment during tumor progression and anti-CTLA-4 antibody immunotherapy effect depends on the expression level of immune factors.

Gomisin M2 from Baizuan suppresses breast cancer stem cell proliferation in a zebrafish xenograft model.

Gomisin M2 isolated from Schisandra viridis A. C. Smith has potential anti-tumor effects on certain cancers, including breast cancer. However, only a few investigations have been conducted on the effects of Gomisin M2 on breast cancer stem cells (CSCs), which have the ability to self-renew and differentiate, as a possible strategy to resolve cancer cell resistance to apoptosis and to improve treatments. It is essential to investigate the effects of Gomisin M2 on breast cancer stem cells (BCSCs). In this study, we enriched breast cancer stem cells with CD44+/CD24- from MDA-MB-231 and HCC1806 cells through magnetic-activated cell sorting and cultured these in serum-free medium. The ability of Gomisin M2 to kill breast cancer stem cells was evaluated in vitro and in vivo. Gomisin M2 significantly inhibited the proliferation of the triple-negative breast cancer cell lines and mammosphere formation in breast CSCs and downregulated the Wnt/ß-catenin self-renewal pathway. Moreover, Gomisin M2 induced apoptosis and blocked the mitochondrial membrane potential of BCSCs. Gomisin M2 suppressed the proliferation of MDA-MB-231 and HCC1806 xenografts in zebrafish. Together, these findings suggest that the anti-BCSC activity of Gomisin M2 could become a promising starting point for the discovery of novel BCSC-targeting drugs.

Resveratrol loaded oxidized mesoporous carbon nanoparticles: A promising tool to treat triple negative breast cancer.

Currently, breast cancer has become the most commonly diagnosed malignancy among females and triple negative breast cancer (TNBC) is a highly aggressive and metastatic subtype. The natural polyphenolic compound, resveratrol (3, 4', 5-trihydroxy-trans-stilbene, RES), has drawn great attention for its potential against TNBC. However, due to the poor aqueous solubility, the bioactivity of RES against TNBC is extremely hampered. In this study, oxidized mesoporous carbon nanoparticles (oMCNs) with size below 200 nm and excellent water dispersibility were synthesized using mild oxidation method and RES was successfully encapsulated into the pores of oMCNs with high drug loading efficiency (24.8% w/w). oMCNs exhibited good biocompatibility and excellent cellular uptake efficiency. Compared to pure RES, oMCNs-RES greatly improved the saturated solubility and in vitro release property. In vitro cytoxicity assay and apoptosis analysis showed that oMCNs-RES induced enhanced cytotoxic effect and pro-apoptosis effect mediated via the PARP and Caspase-3 protein cleavage in TNBC cell line, respectively. These results demonstrate oMCNs have the potential to deliver hydrophobic drugs and oMCNs-RES are promising in treating TNBC.

Subcutaneous inoculation position affects the immune environment in CT26 carcinomas.

Comprehensive knowledge on the murine CT26 colon carcinoma line is a classic model used in the pharmacodynamic experiments involving IDO-1 inhibitors, immune-related checkpoint antibodies and immune related mechanisms. In this study, we determined the impact of different subcutaneous inoculation locations on tumor growth and immune factor expression. CT26 cells were treated with the IDO-1 inhibitor, INCB024360, following INF-γ stimulation and analyzed for kynurenine concentration. Female Balb/c mice were inoculated with CT26 cells in either or both the right upper flank or the right lower flank. Isolated tumors were evaluated for changes in tumor volume following treatment with anti-PD-1, anti-CTLA-4, or no treatment. Isolated tumors were also evaluated for changes in immune cell subpopulations and expression of key immune factors using FACS. Treatment of two CT26 cell lines with INCB024360 produced similar results. IC50 values were 222.5 and 276.0, and the peak inhibitory rates were 97.99% and 91.85% respectively. Analysis of tumor growth revealed that tumor volumes were larger (1925 mm3 vs. 767 mm3), and the anti-tumor effects of both anti-PD-1 and anti-CTLA-4 were different in mice inoculated in the right lower flank than in those inoculated in the upper flank. FACS analysis revealed that the CD8+T subpopulation in the right upper flank was higher than that in the lower flank (*P < 0.05). By contrast, the myeloid cell populations was lower in the right upper flank than it was in the right lower flank (*P < 0.05). The INF-γ populations in CD8+T (*P < 0.05) and regulatory T (Treg) cell subpopulation (*P < 0.05) were also more abundant in the right upper flank than in the right lower flank. In contrast to the uniform of the results from the in vitro experiment, the anti-CTLA-4 and anti-PD-1 antibodies had different efficacies depending on the location of the subcutaneous inoculation of CT26 in mice. The differences in the percentages of CD8+T, myeloid cells, INF-γ in CD8+T, and Treg subpopulations indicated that the tumor microenvironment was affected by inoculation position. Taken together, these results suggest that tumors isolated from same cell line with different inoculation positions are different enough to be considered different models.

Garcinone C exerts antitumor activity by modulating the expression of ATR/Stat3/4E­BP1 in nasopharyngeal carcinoma cells.

Nasopharyngeal carcinoma (NPC) is one of the most common head and neck malignancies and is typically treated with radiotherapy and chemotherapy. Garcinone C, a natural compound isolated from Garcinia oblongifolia Champ., is a xanthone derivative with potential cytotoxic effects on certain cancers. However, there are limited studies regarding its effects on NPC cells, and its mechanism of action in NPC remains unknown. In the present study, we found that garcinone C significantly inhibited cell viability of the human NPC cell lines CNE1, CNE2, HK1 and HONE1. This inhibition was exerted in a time­ and dose­dependent manner. Flow cytometry demonstrated that garcinone C arrested the cell cycle at the S phase. Moreover, with 10 µM of high­dose garcinone C treatment, the cells exhibited necrotic morphology changes including cell swelling, rough endoplasmic reticulum degranulation, endoplasmic reticulum dilatation, mitochondrial swelling and vacuolar degeneration. In addition, we found that garcinone C stimulated the expression levels of ATR and 4E­BP1, while efficiently inhibiting the expression levels of cyclin B1, cyclin D1, cyclin E2, cdc2, CDK7 and Stat3. Collectively, the ability of garcinone C to inhibit NPC in growth in vitro suggested that garcinone C may be a novel agent for the management of NPC.

Skp2 is associated with paclitaxel resistance in prostate cancer cells.

Prostate cancer is the most commonly diagnosed tumor in men in the United States. Patients with hormone-refractory prostate cancer are often treated with paclitaxel, but most of them eventually develop drug resistance. S-phase kinase associated protein 2 (Skp2) is a component of the SCF (Skp1-Cullin1-F-box) type of E3 ubiquitin ligase complexes. In the present study, we investigated the role of Skp2 in paclitaxel-resistant DU145-TxR or PC-3-TxR cells by Skp2 silencing or using Skp2 inhibitors. We first confirmed that Skp2 expression is up-regulated in DU145-TxR or PC-3-TxR cells compared with their parental cells DU145 or PC-3, respectively. Knockdown of Skp2 or Skp2 inhibitor treatment in DU145-TxR or PC-3-TxR cells restored paclitaxel sensitivity. E-cadherin was decreased while Vimentin was increased in PC-3-TxR or DU145-TxR cells. In addition, p27 expression was inversely correlated with Skp2 expression in DU145-TxR or PC-3-TxR cells. Moreover, p27 was found to increase in both Skp2 silencing PC-3-TxR and DU145-TxR cells. These results suggest that Skp2 is associated with prostate cancer cell resistance to paclitaxel. Skp2 may be a potential therapeutic target for drug-resistant prostate cancer.