Desulfurative Functionalization of ß-Acyl Allylic Sulfides with N-H Free Indoles Highly Regioselective at C3 and N1 Positions: Rapid Access to α-Branched Enones.

A regiodivergent allylation of 1H-indoles highly selectively at the C3 and N1 positions with ß-acyl allylic sulfides through desulfurative C-C/C-N bond-forming reactions has been developed under mild conditions. Notably, the remarkable site-selective switch can be achieved by a delicate choice of solvents and bases. This cost-efficient method displays a broad substrate scope, good functional compatibility, and excellent site-selectivity, thus offering a divergent synthesis of indole substituted α-branched enones, which possess diverse potential opportunities for further applications and derivatization.

Let-7a regulates EV secretion and mitochondrial oxidative phosphorylation by targeting SNAP23 in colorectal cancer.

BACKGROUND: MicroRNAs (miRNAs) are abundant in tumor-derived extracellular vesicles (EVs) and the functions of extracellular miRNA to recipient cells have been extensively studied with tumorigenesis. However, the role of miRNA in EV secretion from cancer cells remains unknown. METHODS: qPCR and bioinformatics analysis were applied for determining extracellular let-7a expression from CRC patient serum and cells. Nanosight particle tracking analysis was performed for investigating the effect of let-7a on EV secretion. Luciferase reporter assays was used for identifying targeted genes synaptosome-associated protein 23 (SNAP23). In vitro and in vivo assays were used for exploring the function of let-7a/SNAP23 axis in CRC progression. Bioenergetic assays were performed for investigating the role of let-7a/SNAP23 in cellular metabolic reprogramming. RESULTS: let-7a miRNA was elevated in serum EVs from CRC patients and was enriched in CRC cell-derived EVs. We determined that let-7a could suppress EV secretion directly targeting SNAP23. In turn, SNAP23 promotes EV secretion of let-7a to downregulate the intracellular let-7a expression. In addition, we found a novel mechanism of let-7a/SNAP23 axis by regulating mitochondrial oxidative phosphorylation (OXPHOS) through Lin28a/SDHA signaling pathway. CONCLUSIONS: Let-7a plays an essential role in not only inhibiting EV secretion, but also suppressing OXPHOS through SNAP23, resulting in the suppression of CRC progression, suggesting that let-7a/SNAP23 axis could provide not only effective tumor biomarkers but also novel targets for tumor therapeutic strategies.

TET1 downregulates epithelial-mesenchymal transition and chemoresistance in PDAC by demethylating CHL1 to inhibit the Hedgehog signaling pathway.

Chemoresistance is a major obstacle to prolonging pancreatic ductal adenocarcinoma (PDAC) patient survival. TET1 is identified as the most important epigenetic modification enzyme that facilitates chemoresistance in cancers. However, the chemoresistance mechanism of TET1 in PDAC is unknown. This study aimed to determine the role of TET1 in the chemoresistance of PDAC. TET1-associated chemoresistance in PDAC was investigated in vitro and in vivo. The clinical significance of TET1 was analyzed in 228 PDAC patients by tissue microarray profiling. We identified that TET1 downregulation is caused by its promoter hypermethylation and correlates with poor survival in PDAC patients. In vitro and in vivo functional studies performed by silencing or overexpressing TET1 suggested that TET1 is able to suppress epithelial-mesenchymal transition (EMT) and sensitize PDAC cells to 5FU and gemcitabine. Then RNA-seq, whole genome bisulfite sequencing (WGBS) and ChIP-seq were used to explore the TET1-associated pathway, and showed that TET1 promotes the transcription of CHL1 by binding and demethylating the CHL1 promoter, which consequently inhibits the Hedgehog pathway. Additionally, inhibiting Hedgehog signaling by CHL1 overexpression or the Hedgehog pathway inhibitor, GDC-0449, reversed the chemoresistance induced by TET1 silencing. Regarding clinical significance, we found that high TET1 and high CHL1 expression predicted a better prognosis in resectable PDAC patients. In summary, we demonstrated that TET1 reverses chemoresistance in PDAC by downregulating the CHL1-associated Hedgehog signaling pathway. PDAC patients with a high expression levels of TET1 and CHL1 have a better prognosis.

USP10 regulates Musashi-2 stability via deubiquitination and promotes tumour proliferation in colon cancer.

Recent studies have demonstrated that ubiquitin-specific protease 10 (USP10) plays a catalytic role in tumour suppression mainly by deubiquitinating its target proteins to enhance their stabilities. However, we found that USP10 could interact with and regulate the expression of oncogenic factor Musashi-2 (MSI2). We investigated whether USP10 positively regulates the expression of MSI2 by deubiquitination and confirmed the type of polyubiquitin chain that is linked to MSI2. We also explored the role of USP10 in regulating the proliferation of colon cancer through different experiments. This study provides a completely new perspective in understanding the role of USP10 in deubiquitination. In the future, USP10 may serve as a target for colon cancer treatment.

Cartilage oligomeric matrix protein is a prognostic factor and biomarker of colon cancer and promotes cell proliferation by activating the Akt pathway.

PURPOSE: Recent studies have determined that cartilage oligomeric matrix protein (COMP) plays a vital role in carcinogenesis. We sought to clarify the role of COMP in colon cancer. METHODS: We investigated gene expression data from The Cancer Genome Atlas (TCGA) dataset. Tissue microarrays (TMA) containing paired samples from 253 patients with colon cancer were subjected to immunostaining. COMP levels in serum of colon cancer patients and healthy donors were measured with ELISA. We established COMP-knockout cells using the CRISPR/Cas9 system and COMP-overexpressing cells using lentiviral vectors to detect the effects of COMP on colon cancer cells using Cell Counting Kit-8 (CCK8), colony formation, apoptosis detection kit, and tumorigenesis assays in nude mice. RESULTS: The analysis of TCGA dataset and the results of the TMA suggested that COMP expression levels were significantly higher in cancer tissues than in adjacent normal tissues. Moreover, high COMP expression was correlated with the poor outcome of colon cancer patients. COMP levels in the sera of preoperative patients with colon cancer were much higher than those in healthy donors and were significantly reduced after colectomy. Colon cancer cells without COMP were defective with respect to the ability to proliferate, colony formation, the ability to resist 5-Fluorouracil-induced apoptosis and the growth of xenograft tumors in mice. Contrasting results were observed in COMP overexpressed cells. COMP promoted colon cancer cell proliferation partially through the activation of PI3K/ Akt/ mTOR/ p70S6K pathway. CONCLUSIONS: COMP may be a novel prognostic indicator and biomarker and also a potential therapeutic target for colon cancer.

Lentivirus-mediated silencing of rhomboid domain containing 1 suppresses tumor growth and induces apoptosis in hepatoma HepG2 cells.

Rhomboids were identified as the first intramembrane serine proteases about 10 years ago. Since then, the study of the rhomboid protease family has blossomed. Rhomboid domain containing 1 (RHBDD1), highly- expressed in human testis, contains a rhomboid domain with unknown function. In the present study, we tested the hypothesis that RHBDD1 was associated with proliferation and apoptosis in hepatocellular carcinoma using recombinant lentivirus-mediated silencing of RHBDD1 in HepG2 cells. Our results showed that down-regulation of RHBDD1 mRNA levels markedly suppressed proliferation and colony formation capacity of HepG2 human hepatoma cancer cells in vitro, and induced cell cycle arrest. We also found that RHBDD1 silencing could obviously trigger HepG2 cell apoptosis. In summary, it was demonstrated that RHBDD1 might be a positive regulator for proliferative and apoptotic characteristics of hepatocellular carcinoma.

Inhibition of Csn3 expression induces growth arrest and apoptosis of hepatocellular carcinoma cells.

PURPOSE: Csn3 (or CSN3) encodes the third subunit of an eight-subunit complex, the COP9 signalosome (CSN), which acts as a protein kinase and a deneddylase in mammalian cells. Previous studies have shown that Csn3 is essential for maintenance of cell proliferation in the mouse embryonic epiblast and associated with the tumorigenesis process in osteosarcoma. However, its correlation with hepatocellular carcinoma (HCC) has not been explored yet. METHODS: The expression of Csn3 in HCC (n = 30), cirrhosis (n = 30), and normal tissues (n = 30) was detected using immunohistochemical analysis. The impacts of lentivirus-mediated inhibition of Csn3 on HCC cells were detected using MTT, BrdU incorporation assay, and flow cytometric analysis. In addition, the colony formation and tumor growth ability in nude mice were detected to define the role of Csn3 in tumorigenesis. RESULTS: Knockdown of Csn3 expression in HCC cell lines (SMMC-7721 and Hep3B) significantly inhibits the tumor growth both in vitro and in vivo. Further investigation indicates that this growth inhibition effect may be mediated through cell cycle arrest in G0/G1 phase and inductions of pro-apoptotic proteins BIK and Caspase-8. In addition, knockdown of Csn3 expression evidently suppresses tumor growth in a xenograft nude mice model. CONCLUSION: Collectively, this study demonstrates Csn3 as an oncogene that regulates the tumorigenesis process in HCC cells.

[Clinical observation on pricking blood along meridians combined with electroacupuncture for treatment of prolapse of lumbar intervertebral disc].

OBJECTIVE: To observe the therapeutic effects on pricking blood along meridians combined with electroacupuncture for treatment of prolapse of lumbar intervertebral disc. METHODS: One hundred cases were randomly divided into an observation group (50 cases) and a control group (50 cases). The observation group was treated with pricking blood along meridians combined with electroacupuncture. The main points for pricking blood were collaterals with blood stasis around Weizhong (BL 40) on the affected side, and collaterals with blood stasis on corresponding meridians such as Foot Shaoyang Meridian, Foot Taiyang Meridian and Foot Yangming Meridian according to body parts syndrome differentiation could also be used. The points for electroacupuncture included Ashi point (1 cun away from the spinal space of segmental lesions), Dachangshu (BL 25), Guanyuanshu (BL 26), Zhibian (BL 54), Huantiao (GB 30) and so on. The control group was only treated with electroacupuncture and treatment was same as the observation group. The therapeutic effects and scores of Visual Analogue Scale (VAS) of two groups were compared. RESULTS: The cured rate of observation group (68.0%, 34/50) was higher than that of control group (46.0%, 23/50, P < 0.05). The cured and markedly effective rate of observation group (92.0%, 46/50) was also higher than that of control group (74.0%, 37/50, P < 0.05). The scores of VAS after treatment in both groups decreased obviously (both P < 0.01), and the decreasing degree of VAS in observation group was more obvious than that in control group (P < 0.01). CONCLUSION: Pricking blood along meridians combined with electroacupuncture has outstanding effect for treatment of prolapse of lumbar intervertebral disc.