IntroductionMultiple myeloma (MM) or plasma cell myeloma is characterized by latent accumulation of secretory plasma cells with a low proliferative index and an extended life span in the bone marrow. 1 The second most prevalent hematologic cancer after non-Hodgkin lymphoma, multiple myeloma accounts for 10% of all hematologic cancers and approximately 2% of all cancer deaths. Conventional therapy for multiple myeloma involves combinations of vincristine, carmustine (bischloroethylnitrosourea), melphalan, cyclophosphamide, doxorubicin (Adriamycin), and prednisone or dexamethasone. 2 Patients younger than 65 years are usually given high-dose melphalan with autologous stem cell support, and older patients or those who cannot tolerate such intensive treatment are given standard-dose oral melphalan and dexamethasone. Shortcomings of these treatments are low remission rates (about 5%), short survival times (median, 30-36 months), and the development of drug resistance. 3,4 Chemoresistance remains a major therapeutic challenge in MM. The precise mechanism underlying chemoresistance in multiple myeloma is not clear, but one of the main contributors to both chemoresistance and pathogenesis is thought to be activation of NF-B and STAT3 and dysregulation of apoptosis. [4][5][6][7][8] Overexpression of antiapoptotic molecules has been linked to chemoresistance in MM; in one study, expression of the antiapoptotic protein Bcl-xL correlated with chemoresistance, with chemoresponse rates of 83% to 87% among non-Bcl-xL-expressing cases but only 20% to 31% among Bcl-xL-expressing cases. 9 Chemoresistance in several types of cancer has been linked to activation of NF-B, a transcription factor with central roles in the regulation of cell growth, survival, angiogenesis, cell adhesion, and apoptosis. 10 Progression and chemoresistance are also thought to involve interleukin 6 (IL-6), expression of which is induced by NF-B, through its regulation of the growth and survival of tumor cells. 11,12 IL-6 leads to constitutive activation of STAT3, which in turn results in expression of high levels of Bcl-xL. 6 Bcl-2 overexpression, another important characteristic of many multiple myeloma cell lines, 13 can rescue cells from glucocorticoid-induced apoptosis. 4 Cell lines resistant to doxorubicin (eg, RPMI 8226-Dox-40) have been shown to overexpress Bcl-xL. 9 Thus, both constitutive activation of NF-B and STAT3 play an important role in chemoresistance, and inhibition of NF-B and STAT3 may overcome this chemoresistance.The use of natural agents may be able to overcome resistance without some of the debilitating side effects of conventional chemotherapy. One such agent is resveratrol, a polyphenol (trans-3, The publication costs of this article were defrayed in part by page charge payment. Therefore, and solely to indicate this fact, this article is hereby marked ''advertisement'' in accordance with 18 USC section 1734. For personal use only. on March 22, 2019. by guest www.bloodjournal.org From 4Ј, 5-trihydroxystilbene) abundant in red grape...

Purpose: Curcumin, a component of turmeric, has been shown to suppress inflammation and angiogenesis largely by inhibiting the transcription factor nuclear factor-nB (NF-nB). This study evaluates the effects of curcumin on ovarian cancer growth using an orthotopic murine model of ovarian cancer. Experimental Design: In vitro and in vivo experiments of curcumin with and without docetaxel were done using human ovarian cancer cell lines SKOV3ip1, HeyA8, and HeyA8-MDR in athymic mice. NF-nB modulation was ascertained using electrophoretic mobility shift assay. Evaluation of angiogenic cytokines, cellular proliferation (proliferating cell nuclear antigen), angiogenesis (CD31), and apoptosis (terminal deoxynucleotidyl transferase^mediated dUTP nick end labeling) was done using immunohistochemical analyses. Results: Curcumin inhibited inducible NF-nB activation and suppressed proliferation in vitro. In vivo dose-finding experiments revealed that 500 mg/kg orally was the optimal dose needed to suppress NF-nB and signal transducers and activators of transcription 3 activation and decrease angiogenic cytokine expression. In the SKOV3ip1 and HeyA8 in vivo models, curcumin alone resulted in 49% (P = 0.08) and 55% (P = 0.01) reductions in mean tumor growth compared with controls, whereas when combined with docetaxel elicited 96% (P < 0.001) and 77% reductions in mean tumor growth compared with controls. In mice with multidrugresistant HeyA8-MDR tumors, treatment with curcumin alone and combined with docetaxel resulted in significant 47% and 58% reductions in tumor growth, respectively (P = 0.05). In SKOV3ip1 and HeyA8 tumors, curcumin alone and with docetaxel decreased both proliferation (P < 0.001) and microvessel density (P < 0.001) and increased tumor cell apoptosis (P < 0.05).Conclusions: Based on significant efficacy in preclinical models, curcumin-based therapies may be attractive in patients with ovarian carcinoma.

Taxol is the best anticancer agent that has ever been isolated from plants, but its major disadvantage is its dose-limiting toxicity. In this study, we report with mechanism-based evidence that curcumin, a nontoxic food additive commonly used by the Indian population, sensitizes tumor cells more efficiently to the therapeutic effect of Taxol

The activation of signal transducers and activators of transcription 3 (STAT3) has been linked with the proliferation of a variety of human cancer cells, including multiple myeloma. Agents that can suppress STAT3 activation have potential for prevention and treatment of cancer. In the present report, we tested an agent, ursolic acid, found in basil, apples, prunes, and cranberries, for its ability to suppress STAT3 activation. We found that ursolic acid, a pentacyclic triterpenoid, inhibited both constitutive and interleukin-6 -inducible STAT3 activation in a dose-and time-dependent manner in multiple myeloma cells. The suppression was mediated through the inhibition of activation of upstream kinases c-Src, Janus-activated kinase 1, Janus-activated kinase 2, and extracellular signalregulated kinase 1/2. Vanadate treatment reversed the ursolic acid -induced down-regulation of STAT3, suggesting the involvement of a tyrosine phosphatase. Indeed, we found that ursolic acid induced the expression of tyrosine phosphatase SHP-1 protein and mRNA. Moreover, knockdown of SHP-1 by small interfering RNA suppressed the induction of SHP-1 and reversed the inhibition of STAT3 activation, thereby indicating the critical role of SHP-1 in the action of this triterpene. Ursolic acid down-regulated the expression of STAT3-regulated gene products such as cyclin D1, Bcl-2, Bcl-xL, survivin, Mcl-1, and vascular endothelial growth factor. Finally, ursolic acid inhibited proliferation and induced apoptosis and the accumulation of cells in G 1 -G 0 phase of cell cycle. This triterpenoid also significantly potentiated the apoptotic effects of thalidomide and bortezomib in multiple myeloma cells. Overall, these results suggest that ursolic acid is a novel blocker of STAT3 activation that may have a potential in prevention and treatment of multiple myeloma and other cancers. (Mol Cancer Res 2007;5(9):943 -55)

BackgroundThe R192Q mutation of the CACNA1A gene, encoding for the α1 subunit of voltage-gated P/Q Ca2+ channels (Cav2.1), is associated with familial hemiplegic migraine-1. We investigated whether this gain-of-function mutation changed the structure and function of trigeminal neuron P2X3 receptors that are thought to be important contributors to migraine pain.ResultsUsing in vitro trigeminal sensory neurons of a mouse genetic model knockin for the CACNA1A R192Q mutation, we performed patch clamp recording and intracellular Ca2+ imaging that showed how these knockin ganglion neurons generated P2X3 receptor-mediated responses significantly larger than wt neurons. These enhanced effects were reversed by the Cav2.1 blocker ω-agatoxin. We, thus, explored intracellular signalling dependent on kinases and phosphatases to understand the molecular regulation of P2X3 receptors of knockin neurons. In such cells we observed strong activation of CaMKII reversed by ω-agatoxin treatment. The CaMKII inhibitor KN-93 blocked CaMKII phosphorylation and the hyperesponsive P2X3 phenotype. Although no significant difference in membrane expression of knockin receptors was found, serine phosphorylation of knockin P2X3 receptors was constitutively decreased and restored by KN-93. No change in threonine or tyrosine phosphorylation was detected. Finally, pharmacological inhibitors of the phosphatase calcineurin normalized the enhanced P2X3 receptor responses of knockin neurons and increased their serine phosphorylation.ConclusionsThe present results suggest that the CACNA1A mutation conferred a novel molecular phenotype to P2X3 receptors of trigeminal ganglion neurons via CaMKII-dependent activation of calcineurin that selectively impaired the serine phosphorylation state of such receptors, thus potentiating their effects in transducing trigeminal nociception.