Chanan-Khan, Asher

AbstractIn a continuing search for curcuminoid (CUR) compounds with antitumor activity, a novel series of heterocyclic CUR–BF2 adducts and CUR compounds based on indole, benzothiophene, and benzofuran along with their aryl pyrazoles were synthesized. Computational docking studies were performed to compare binding efficiency to target proteins involved in specific cancers, namely HER2, proteasome, VEGFR, BRAF, and Bcl‐2, versus known inhibitor drugs. The majority presented very good binding affinities, similar to, and even more favorable than those of known inhibitors. The indole‐based CUR–BF2 and CUR compounds and their bis‐thiocyanato derivatives exhibited high anti‐proliferative and apoptotic activity by in vitro bioassays against a panel of 60 cancer cell lines, more specifically against multiple myeloma (MM) cell lines (KMS11, MM1.S, and RPMI‐8226) with significantly lower IC50 values versus healthy PBMC cells; they also exhibited higher anti‐proliferative activity in human colorectal cancer cells (HCT116, HT29, DLD‐1, RKO, SW837, and Caco2) than the parent curcumin, while showing notably lower cytotoxicity in normal colon cells (CCD112CoN and CCD841CoN).

BACKGROUNDOutcomes have improved significantly in multiple myeloma (MM), but racial disparities in health care access and survival exist. A comprehensive analysis exploring MM care and racial disparities is warranted.METHODSPatients with MM from 1991 to 2010 in the Surveillance, Epidemiology, and End Results‐Medicare database were evaluated for racial trends in clinical myeloma‐defining events (MDEs), the receipt of treatment (drugs and stem cell transplantation; [SCT]), the cost of care, and overall survival (OS).RESULTSAmong 35,842 patients, the frequency of all MDEs at diagnosis increased over time; whereas, in recent years (2006‐2010), all MDEs with the exception of renal dialysis decreased. Blacks had highest rates for all MDEs except bone fractures, which were highest in whites. Over time, the proportion of patients who received any treatment, multiple agents, and SCT increased significantly, and the largest increase was observed in the receipt of immunomodulatory drugs and steroids. There was greater receipt of bortezomib and SCT among whites and blacks and higher receipt of immunomodulatory drugs among Hispanics and Asians (P < .001). Medicare claims were highest during first 6 months after MM diagnosis for blacks and at any time after MM diagnosis for Hispanics. Over time, Medicare claims increased most steadily for Hispanics (P < .001). Hypercalcemia, renal dysfunction, and bone fractures were associated with inferior OS. Blacks and Asians had superior OS compared with whites, but racial differences in OS became less pronounced during 2006 through 2010 (P = .182) compared with prior years (P < .01). Better OS was noted among patients who had higher median incomes.CONCLUSIONSThe current results indicate that there have been significant changes in the management of patients with MM over time and provide an in‐depth understanding of the factors that may help explain racial disparities. Cancer 2018;124:1710‐21. © 2018 American Cancer Society

BACKGROUNDNational Cancer Institute (NCI)/National Comprehensive Cancer Network (NCCN)–designated cancer centers (CCs) offer patients state‐of‐the‐art treatment, but their impact on multiple myeloma (MM) patient outcomes has not been evaluated.METHODSAdult MM patients diagnosed between 1973 and 2011 were identified from the Surveillance, Epidemiology, and End Results database and were stratified by the county of residence at the time of diagnosis and the year of CC designation. The influence of NCI/NCCN CC access, race, and the year of diagnosis on overall survival (OS) was evaluated with a Cox regression model.RESULTSA statistically significant OS improvement was noted in patients diagnosed after 1995 with access to 2 or more NCI CCs overall (P = .002 for 1996‐2002; P < .001 for 2003‐2011) and by race for whites (hazard ratio [HR] for 1996‐2002, 0.85; 95% confidence interval [CI], 0.78‐0.91; HR for 2003‐2011, 0.85; 95% CI, 0.79‐0.91) but not for nonwhites. For NCCN access, improvement was seen in 1996‐2002 (P = .003), in 2003‐2011 (P < .001), and by race for whites (HR, 0.917; 95% CI, 0.88‐0.95) and nonwhites (0.94; 95% CI, 0.89‐0.99), but within nonwhites, this was true only for African Americans (AAs; HR, 0.88; 95% CI, 0.81‐0.97) and not for Asians, Hispanics, or Native Americans.CONCLUSIONSImprovement in OS was seen in MM patients diagnosed after 1995 with access to 1 NCCN CC or 2 or more NCI CCs. NCI access benefited only whites, whereas NCCN access benefited only white and AA patients. No OS benefit was seen for any subgroup with access to only 1 NCI center. Eliminating racial disparities in health care access and utilization is needed to improve outcomes. Cancer 2016;122:618–625. © 2015 American Cancer Society.

The ubiquitin–proteasome system (UPS) is increasingly recognized as a therapeutic target for the development of anticancer therapies. The success of the 20S proteasome core particle (20S CP) inhibitor bortezomib in the clinical management of multiple myeloma has raised the possibility of identifying other UPS components for therapeutic intervention. We previously identified the small molecule b‐AP15 as an inhibitor of 19S proteasome deubiquitinase (DUB) activity. Building upon our previous data, we performed a structure–activity relationship (SAR) study on b‐AP15 and identified VLX1570 as an analog with promising properties, including enhanced potency and improved solubility in aqueous solution. In silico modeling was consistent with interaction of VLX1570 with key cysteine residues located at the active sites of the proteasome DUBs USP14 and UCHL5. VLX1570 was found to inhibit proteasome deubiquitinase activity in vitro in a manner consistent with competitive inhibition. Furthermore, using active‐site‐directed probes, VLX1570 also inhibited proteasome DUB activity in exposed cells. Importantly, VLX1570 did not show inhibitory activity on a panel of recombinant non‐proteasome DUBs, on recombinant kinases, or on caspase‐3 activity, suggesting that VLX1570 is not an overtly reactive general enzyme inhibitor. Taken together, our data shows the chemical and biological properties of VLX1570 as an optimized proteasome DUB inhibitor.

SummaryMultiple myeloma, the second most common haematological malignancy in the U.S., is currently incurable. Disruption of the intrinsic apoptotic pathway by BCL2 and MCL1 upregulation is observed in >80% of myeloma cases and is associated with an aggressive clinical course. Remarkably, there is no approved drug with the ability to target BCL2 or MCL1. Thus, we investigated the anti‐tumour effects of a pan‐BCL2 inhibitor, AT‐101, which has high binding specificity for BCL2 and MCL1 in preclinical models of plasma cell cancers (Multiple myeloma and Waldenström macroglobulinaemia). Gene expression and immunoblot analysis of six plasma cell cancer models showed upregulation of BCL2 family members. AT‐101 was able to downregulate BCL2 and MCL1 in all plasma cell cancer models and induced apoptotic cell death in a caspase‐dependent manner by altering mitochondrial membrane permeability. This cytotoxic effect and BCL2 downregulation were further potentiated when AT‐101 was combined with lenalidomide/dexamethasone (LDA). NanoString nCounter mRNA quantification and Ingenuity Pathways Analysis revealed differential changes in the CCNA2, FRZB, FYN, IRF1, PTPN11 genes in LDA‐treated cells. In summary, we describe for the first time the cellular and molecular events associated with the use of AT‐101 in combination with lenalidomide/dexamethasone in preclinical models of plasma cell malignancy.