Multiple myeloma (MM) is still an incurable malignancy of plasma cells. Proteasome inhibitors (PIs) work as the backbone agent and have greatly improved the outcome in majority of newly diagnosed patients with myeloma. However, drug resistance remains the major obstacle causing treatment failure in clinical practice. Here, we investigated the effects of Indirubin-3’-monoxime (I3MO), one of the derivatives of Indirubin, in the treatment of MM. MM patient primary samples and human cell lines were examined. I3MO effects on myeloma treatment and the underling molecular mechanisms were investigated via in vivo and in vitro study. Our results demonstrated the anti-MM activity of I3MO in both drug- sensitive and -resistance MM cells. I3MO sensitizes MM cells to bortezomib-induced apoptosis. Mechanistically, I3MO acts as a multifaceted regulator of cell death, which induced DNA damage, cell cycle arrest, and abrogates NF-κB activation. I3MO efficiently down-regulated USP7 expression, promoted NEK2 degradation, and suppressed NF-κB signaling in MM. Our study reported that I3MO directly bound with and caused the down-regulation of PA28γ (PSME3), and PA200 (PSME4), the proteasome activators. Knockdown of PSME3 or PSME4 caused the inhibition of proteasome capacity and the overload of paraprotein, which sensitizes MM cells to bortezomib-mediated growth arrest. Clinical data demonstrated that PSME3 and PSME4 are over-expressed in relapsed/refractory MM (RRMM) and associated with inferior outcome. Altogether, our study indicates that I3MO is agent triggering proteasome inhibition and represents a promising therapeutic strategy to improve patient outcome in MM. A full list of funding can be found in the acknowledgements.

Purpose: To evaluate the effect of 5-fluorouracil (5-FU) combined with rutaecarpine (RUT) on the antiproliferative, anti-migratory, and apoptosis-promoting ability of colorectal cancer (CRC) cells and explore the underlying mechanism. Methods: The antiproliferative effects of RUT and 5-FU on CRC cells were evaluated using MTT and colony formation assays. Anti-migration was assessed by cell scratch and transwell tests. The synergistic effect of RUT and 5-FU was assessed by isobologram and combination index analysis using CompuSyn software. The effects of RUT and 5-FU on cell apoptosis were detected by flow cytometry. Differences in protein expression levels with or without RUT and/or 5-FU treatment were assessed by Western blot. Moreover, a mouse xenograft model of CRC was established to investigate the antitumor effect of RUT and 5-FU in vivo, and Ki67 and cleaved caspase-3 expression was detected by immunofluorescence. Results: In this study, we found that 5-FU combined with RUT can inhibit the proliferative, migratory, and antiapoptotic abilities of CRC cells to a significantly greater extent than either RUT or 5-FU alone both in vivo and in vitro. Western blot analysis showed that the level of signal transducer and activator of transcription 3 (STAT3) phosphorylation in CRC cells was significantly reduced after combination therapy compared with that seen with the respective monotherapies. In addition, combination therapy influenced the STAT3 signaling pathway, namely, it inhibited the expression of c-Myc, CDK4, and Bcl-2 while enhancing that of the proapoptotic protein cleaved caspase-3. Immunofluorescence staining further showed that the expression of Ki67 and cleaved caspase-3 was significantly downregulated and upregulated, respectively, in tumor tissues of mice treated with combination therapy compared with that observed with 5-FU treatment alone. Conclusion: Combined therapy with 5-FU and RUT exerted a superior curative effect in CRC than treatment with either single drug alone and has potential as a novel therapeutic modality for the treatment of CRC.

Tracing the concept of the reserve from the early days of the nation, from the Constitutional debates of the 18th and 19th centuries, and from the legislation leading to the establishment of the Army Reserve, this Strategy Research Project (SRP) describes the role of the Army Reserve from its beginning as a reserve corps of medical doctors to that of a strategic reserve force, and then to its current operational role. It briefly discusses some of the implications of this evolution on current readiness. Finally, this SRP envisions a future of the Army Reserve to include its role as a strategic reserve in addition to the operational role it is currently fulfilling.

Retraction for the article 5-Fluorouracil Combined with Rutaecarpine Synergistically Suppresses the Growth of Colon Cancer Cells by Inhibiting STAT3