Inhibitors Targeting the F-BOX Proteins.

F-box proteins are involved in multiple cellular processes through ubiquitylation and consequent degradation of targeted substrates. Any significant mutation in F-box protein-mediated proteolysis can cause human malformations. The various cellular processes F-box proteins involved include cell proliferation, apoptosis, invasion, angiogenesis, and metastasis. To target F-box proteins and their associated signaling pathways for cancer treatment, researchers have developed thousands of F-box inhibitors. The most advanced inhibitor of FBW7, NVD-BK M120, is a powerful P13 kinase inhibitor that has been proven to bring about apoptosis in cancerous human lung cells by disrupting levels of the protein known as MCL1. Moreover, F-box Inhibitors have demonstrated their efficacy for treating certain cancers through targeting particular mutated proteins. This paper explores the key studies on how F-box proteins act and their contribution to malignancy development, which fabricates an in-depth perception of inhibitors targeting the F-box proteins and their signaling pathways that eventually isolate the most promising approach to anti-cancer treatments.

A comprehensive comparative study on LSD1 in different cancers and tumor specific LSD1 inhibitors.

LSD1 was significantly over-expressed in several cancer types, and its aberrant overexpression was revealed to play a crucial role in the initiation and progression of cancer. Several LSD1 inhibitors that were discovered and developed so far were found to be effective in attenuating tumor growth in both in vivo and in vitro studies. However, the major challenge associated with the development of cancer therapies is personalized treatment. Therefore, it is essential to look in detail at how LSD1 plays its part in carcinogenesis and whether there are any different expression levels of LSD1 in different tumors. Here in this review, fresh insight into a list of function correlated LSD1 binding proteins are provided, and we tried to figure out the role of LSD1 in different cancer types, including hematological malignancies and solid tumors. A critical description of mutation preference for LSD1 in different tumors was also discussed. Recent research findings clearly showed that the abrogation of LSD1 demethylase activity via LSD1 inhibitors markedly reduced the growth of cancer cells. But there are still many ambiguities regarding the role of LSD1 in different cancers. Therefore, targeting LSD1 for treating different cancers is still reductionist, and many challenges need to be met to improve the therapeutic outcomes of LSD1 inhibitors.

Jaridon 6, a new diterpene from Rabdosia rubescens (Hemsl.) Hara, can display anti-gastric cancer resistance by inhibiting SIRT1 and inducing autophagy.

Tumor resistance is the main cause of treatment failure and is associated with many tumor factors. Jaridon 6, a new diterpene extracted from Rabdosia rubescens (Hemsl.) Hara, which has been previously extracted by our research team, has been tested having more obvious advantages in resistant tumor cells. However, its mechanism is unclear. In this study, we studied the effect and the specific mechanism of Jaridon 6 in resistant gastric cancer cells. Cytotoxicity test, colony test, western blotting, and nude test verified the anti-drug resistance ability of Jaridon 6 in the MGC803/PTX and MGC803/5-Fu cells. Jaridon 6 has shown obvious inhibitory effects in the sirtuin 1 (SIRT1) enzyme test. Transmission electron microscopy and immunofluorescence tests further proved the autophagic action of Jaridon 6. Jaridon 6 could inhibit the proliferation of the resistant gastric cancer cell in vivo and in vitro. Jaridon 6 inhibited SIRT1 enzyme and induced autophagy by inhibiting the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway. Thus, it may be considered for treating gastric cancer resistance by individual or combined administration, as an SIRT1 inhibitor and autophagy inducer.

Generation and characterization of a paclitaxel-resistant human gastric carcinoma cell line.

The main aim of this study was to establish a novel paclitaxel (PTX)-resistant human gastric carcinoma cell line and to investigate its biological significance. A cell line, MGC803/PTX, was established by gradually increasing PTX density on the basis of MGC803 over a period of 10 months. In addition, a pair of resistant cell lines (SW620 and SW620/PTX) were added to further explain the resistant mechanism of PTX. The drug resistance index and stability of MGC803/PTX cells were detected using the Cell Counting Kit-8 method. The morphological features were observed using inverted microscopy. Apoptosis was measured by flow cytometry (FCM) and Hoechst 33258 fluorescence staining. The distribution of the cell cycle was determined by FCM, and protein expressions of P-gp, Bcl-2, Bax, and PARP were detected by western blot analysis. When characterizing the resistance in vitro, we found that MGC803/PTX cells were 10.3-fold more resistant to PTX compared with MGC803 cells. In addition, MGC803/PTX cells showed cross-resistance to 5-fluorouracil and adriamycin. FCM and Hoechst 33258 fluorescence staining indicated that MGC803/PTX cells had a significantly lower percentage of apoptotic cells after treatment with PTX compared with MGC803 cells. Other differences between parental cells and resistant cells included morphology, proliferation rate, doubling time, cell cycle distribution, and colony-formation rate. Western blot analysis indicated that P-gp, Bcl-2, and PARP protein were more abundant in MGC803/PTX and SW620/PTX cells compared with MGC803 and SW620 cells, whereas Bax protein levels were lower in resistant cells. Furthermore, MGC803/PTX cells showed obvious resistance to PTX in vivo. To our knowledge, this is the first report on the establishment of a PTX-resistant MGC803 cell line, which is an important tool to explore the resistance of anticancer drugs and to overcome tumor drug resistance.

Wenyang Huazhuo Tongluo formula, a Chinese herbal decoction, improves skin fibrosis by promoting apoptosis and inhibiting proliferation through down-regulation of survivin and cyclin D1 in systemic sclerosis.

BACKGROUND: Fibrosis is a major contributor to systemic sclerosis (SSc)-related morbidity, and rapid, progressive skin involvement predicts later mortality. Western medicine therapies for SSc cannot produce satisfactory effects currently, while Traditional Chinese Medicine (TCM), such as the Wenyang Huazhuo Tongluo (WYHZTL) formula, a Chinese herbal decoction, has shown amazing anti-fibrosis efficacy on SSc in clinical applications. This study is aiming to investigate the anti-fibrotic mechanism of WYHZTL formula for the treatment of SSc. METHODS: Fibroblasts from primary culture of skin lesions of SSc patients were exposed to rat medicated sera containing WYHZTL or XAV939, a small-molecule inhibitor of both tankyrase 1/2 and Wnt/ß-catenin pathway. Cell counting kit-8 assay and Annexin V FITC/PI apoptosis kit were used to analyze cell proliferation and apoptosis in fibroblasts, respectively. Reverse transcription-polymerase chain reaction (RT-PCR) and western blotting were used to detect the mRNA and protein levels of cyclin D1 and survivin. RESULTS: After 28, 48 and 72 h of incubation, the proliferative ability of the fibroblasts cells was obviously reduced by the sera containing WYHZTL compared with that in the control group; the percentage of apoptotic cell population in the sera containing WYHZTL treated fibroblasts cells was significantly higher than that in those treated with the control sera, and was about similar to that in those treated with XAV939. The sera containing WYHZTL could down-regulate both mRNA and protein levels of cyclin D1 and survivin, compared with the control group. CONCLUSIONS: The present study demonstrates the antiproliferative and pro-apoptotic actions of WYHZTL formula against fibroblasts and the effect may be related to the down-regulation of mRNA and protein levels of cyclin D1 and survivin in SSc.

Two new sesquiterpene lactones from the fruits of Illicium jiadifengpi.

Two new seco-prezizaane-type sesquiterpenes, 3,4-dehydroneomajucin (1) and 1,2,3,4-tetradehydroneomajucin (2), were isolated from the fruits of Illicium jiadifengpi. The structure of these compounds was determined using 1D and 2D NMR and ESI-MS. The isolates were evaluated for their anti-hepatitis B virus activities on the Hep G2.2.15 cell line. The inhibitory rates of compounds 1 and 2 on the HBeAg and HBsAg expression were 30.08 ± 3.09% and 11.43 ± 1.92% at a concentrations of 68.00 µM and 7.88 ± 1.21% and 16.96 ± 4.24% at a concentration of 68.50 µM, respectively.

A new sesquiterpene lactone from the fruits of Illicium henryi.

AIM: To study the chemical constituents of the fruits of Illicium henryi. METHOD: Chromatographic separations on silica gel, Sephadex LH-20 gel and MCI gel were used to isolate the compounds. The structures were elucidated based on extensive spectroscopic data analyses. RESULTS: Seven compounds were obtained and their structures were identified as 10-benzoyl-cycloparvifloralone (1), cycloparvifloralone (2), 2α-hydroxycycloparviforalone (3), henrylactone B (4), merrillianone (5), henrylactone C (6) and 7, 14-ortholactone- 3-hydroxyfloridanolide (7). CONCLUSION: Compound 1 is a new sesquiterpene lactone. The tested compounds showed weak anti-HBV activities on HBV surface antigen (HBsAg) secretion and HBV e antigen (HBeAg) secretion using Hep G2.2.15 cell line.

Isolation, characterization and cytotoxic activity of benzophenone glucopyranosides from Mahkota Dewa (Phaleria macrocarpa (Scheff.) Boerl).

Two benzophenone glucopyranosides have been isolated from the nut shell part of Mahkota Dewa. The structures were identified as 2,4',6-trihydroxy-4-methoxy-benzophenone-2-O-ß-d-glucoside (Mahkoside A) and 2,4',6-trihydroxy-4-methoxy-6″-acetyl-benzophenone-2-O-ß-d-glucoside (Mahkoside B). Mahkoside B was recognized as a novel compound. Furthermore, a series of benzophenone glucopyranoside derivatives (compounds 3-18) were synthesized and their bioactivities were characterized. Our results demonstrated that compound 18 has significant cytotoxicity against two esophageal cancer cell lines, stomach cancer cell line and prostate cancer cell line, with IC(50) less than 10 µM, indicating its potential activity against cancer cells.

[Study on the chemical constituents of Selaginella tamariscina (Beauv.) Spring].

AIM: To study the chemical constituents of Selaginella tamariscina (Beauv.) Spring. METHODS: Various chromatographic techniques were used to separate and purify the chemical constituents. Their physico-chemical properties and spectral data were used to elucidate the structures. RESULTS: Four compounds were isolated from the n-BuOH fraction of the water-extracts. Their structures were identified as 1-hydroxy-2-[2-hydroxy-3-methoxy-5-(1-hydroxyethyl)-phenyl]-3-(4-hydroxy-3,5-dimethoxy)-propane-1-O-beta-D-glucopyranoside (tamariscinoside B, I), adenosine (II), guanosine (III), arbutin (IV). CONCLUSION: Tamariscinoside B (I) is a new compound, while the others were isolated from Selaginella for the first time.