Antiproliferative activities and SAR studies of substituted anthraquinones and 1,4-naphthoquinones.

STAT3 is constitutively active in a large variety of cancers. The search for STAT3 inhibitors led to the discoveries of LLLs 3 and 12, which are substituted anthraquinones. LLL12 is an extremely potent compound that exhibits high levels of antiproliferative activity. Herein the synthesis and evaluation of compounds containing either an anthraquinone or 1,4-naphthoquinone moiety are reported. Analogs were evaluated in several cancer cell lines. Interestingly, it was found that the anthraquinones did not follow the same trends as the 1,4-naphthoquinones in regards to potency. LLL12, which contains a sulfonamide at position 1, was found to be the most potent of the anthraquinones. In contrast, the methyl ketone and methyl ester derivatives (LLLs 3.1 and 5.1) were found to be the most potent of the 1,4-naphthoquinones. Selected 1,4-naphthoquinones were also evaluated in the STAT3 fluorescence polarization assay in order to evaluate their abilities to bind to the STAT3 SH2 domain. They were found to have similar affinities, and their activities suggest that STAT3 is one of their molecular targets.

Design, synthesis and biological studies of novel tubulin inhibitors.

A series of compounds originally derived from the vascular endothelial growth factor receptor tyrosine kinase inhibitor, SU5416, were synthesized and evaluated. The most potent compound in this series, compound 3, which structurally resembles the potent anti-microtubule agent combretastatin A-4, inhibited tubulin polymerization and showed potent growth inhibitory activities on both prostate and breast cancer lines with IC50 values in the low nanomolar range.

Structure-activity relationship studies of thalidomide analogs with a taxol-like mode of action.

Anti-microtubule agents such as paclitaxel and docetaxel have played an important role in the treatment of cancer for many years. Recently, a small molecule that has a taxol-like mode of action (5HPP-33) was reported. Herein, the detailed structure-activity relationship (SAR) studies of 5HPP-33 analogs that are substituted at the isoindole and phenyl rings are described. Bulky substitutions (such as di-isopropyl groups) on the phenyl ring result in the isoindole and phenyl rings being perpendicular to each other. It was found that this conformation is critical for anti-microtubule activity. These studies have provided valuable information, which will be helpful in the design of more potent analogs.

Anticancer activity and SAR studies of substituted 1,4-naphthoquinones.

In this paper, we report the structure-activity relationship studies of substituted 1,4-naphthoquinones for its anticancer properties. 1,4-Naphthoquinone, Juglone, Menadione, Plumbagin and LLL12.1 were used as lead molecules to design PD compounds. Most of the PD compounds showed improved antiproliferative activity in comparison to the lead molecule in prostate (DU-145), breast (MDA-MB-231) and colon (HT-29) cancer cell lines. PD9, PD10, PD11, PD13, PD14 and PD15 were found to be the most potent compound with an IC0 value of 1-3 µM in all cancer cell lines. Fluorescent polarization assay was employed to study the inhibition of STAT3 dimerization by PD compounds. PD9 and PD18 were found to be potent STAT3 dimerization inhibitors.

The cardiovascular disease burden of non-traumatic fractures for adults with and without cerebral palsy.

BACKGROUND: Individuals with cerebral palsy (CP) are vulnerable to non-trauma fracture (NTFx) and have an elevated burden of cardiovascular disease (CVD) related morbidity and mortality. However, very little is known about the contribution of NTFx to CVD risk among adults with CP. The purpose of this study was to determine if NTFx is a risk factor for CVD among adults with CP and if NTFx exacerbates CVD risk compared to adults without CP. METHODS: Data from 2011 to 2016 Optum Clinformatics® Data Mart and a random 20% sample Medicare fee-for-service were used for this retrospective cohort study. Diagnosis codes were used to identify adults (18+ years) with and without CP, NTFx, incident CVD up to 2 years (i.e., ischemic heart disease, heart failure, cerebrovascular disease), and pre-NTFx comorbidities. Crude incidence rates per 100 person years of CVD measures were estimated. Cox regression estimated hazard ratios (HR and 95% confidence interval [CI]) for CVD measures, comparing: (1) CP and NTFx (CP + NTFx; n = 1012); (2) CP without NTFx (CP w/o NTFx; n = 8345); (3) without CP and with NTFx (w/o CP + NTFx; n = 257,355); and (4) without CP and without NTFx (w/o CP w/o NTFx; n = 4.8 M) after adjusting for demographics and pre-NTFx comorbidities. RESULTS: The crude incidence rate was elevated for CP + NTFx vs. CP w/o NTFx and w/o CP + NTFx for any CVD and for each CVD subtype. After adjustments, the HR was elevated for CP + NTFx vs. CP w/o NTFx for any CVD (HR = 1.16; 95%CI = 0.98-1.38), heart failure (HR = 1.31; 95%CI = 1.01-1.70), and cerebrovascular disease (HR = 1.23; 95%CI = 0.98-1.55); although, only heart failure was statistically significant. The adjusted HR was elevated for CP + NTFx vs. w/o CP + NTFx for any CVD and for each CVD subtype (all P < .05). Stratified analyses showed a higher CVD risk by NTFx location, <65 year olds, and men when comparing CP + NTFx vs. CP w/o NTFx and w/o CP + NTFx. CONCLUSIONS: NTFx increases 2-year CVD risk among adults with CP and compared to adults without CP. Findings suggest that NTFx is a risk factor for CVD among adults with CP.

The respiratory disease burden of non-traumatic fractures for adults with cerebral palsy.

BACKGROUND: Individuals with cerebral palsy (CP) are vulnerable to non-trauma fracture (NTFx) and premature mortality due to respiratory disease (RD); however, very little is known about the contribution of NTFx to RD risk among adults with CP. The purpose of this study was to determine if NTFx is a risk factor for incident RD and if NTFx exacerbates RD risk in the adult CP population. METHODS: Data from 2011 to 2016 Optum Clinformatics® Data Mart and a random 20% sample Medicare fee-for-service were used for this retrospective cohort study. Diagnosis codes were used to identify adults (18+ years) with and without CP, NTFx, incident RD at 3-, 6-, 12-, and 24-month time points (pneumonia, chronic obstructive pulmonary disease, interstitial/pleura disease), and comorbidities. Crude incidence rates per 100 person years of RD were estimated. Cox regression estimated hazard ratios (HR and 95% confidence interval [CI]) for RD measures, comparing: (1) CP and NTFx (CP + NTFx); (2) CP without NTFx (CP w/o NTFx); (3) without CP and with NTFx (w/o CP + NTFx); and (4) without CP and without NTFx (w/o CP w/o NTFx) after adjusting for demographics and comorbidities. RESULTS: The crude incidence rate was elevated for CP + NTFx vs. CP w/o NTFx and w/o CP + NTFx for each RD measure. After adjustments, the HR was elevated for CP + NTFx vs. CP w/o NTFx for pneumonia and interstitial/pleura disease at all time points (all P < 0.05), but not chronic obstructive pulmonary disease (e.g., 24-month HR = 1.07; 95%CI = 0.88-1.31). The adjusted HR was elevated for CP + NTFx vs. w/o CP + NTFx for pneumonia at all time points, interstitial/pleura disease at 12- and 24-month time points, and chronic obstructive pulmonary disease at 24-months (all P < 0.05). There is evidence of a time-dependent effect of NTFx on pneumonia and interstitial/pleura disease for CP + NTFx as compared to CP w/o NTFx. CONCLUSIONS: Study findings suggest that NTFx is a risk factor for incident RD, including pneumonia and interstitial/pleura disease, among adults with CP and that NTFx exacerbates RD risk for adults with vs. without CP.

Structure-activity relationship studies of curcumin analogues.

Two series of curcumin analogues, a total of twenty-four compounds, were synthesized and evaluated. The most potent compound, compound 23, showed potent growth inhibitory activities on both prostate and breast cancer lines with IC(50) values in sub-micromolar range, fifty times more potent than curcumin. Curcumin analogues might be potential anti-tumor agents for breast and prostate cancers.

Efficiently mining Adverse Event Reporting System for multiple drug interactions.

Efficiently mining multiple drug interactions and reactions from Adverse Event Reporting System (AERS) is a challenging problem which has not been sufficiently addressed by existing methods. To tackle this challenge, we propose a FCI-fliter approach which leverages the efforts of UMLS mapping, frequent closed itemset mining, and uninformative association identification and removal. By applying our method on AERS, we identified a large number of multiple drug interactions with reactions. By statistical analysis, we found most of the identified associations have very small p-values which suggest that they are statistically significant. Further analysis on the results shows that many multiple drug interactions and reactions are clinically interesting, and suggests that our method may be further improved with the combination of external knowledge.

Structurally modified curcumin analogs inhibit STAT3 phosphorylation and promote apoptosis of human renal cell carcinoma and melanoma cell lines.

The Janus kinase-2 (Jak2)-signal transducer and activator of transcription-3 (STAT3) pathway is critical for promoting an oncogenic and metastatic phenotype in several types of cancer including renal cell carcinoma (RCC) and melanoma. This study describes two small molecule inhibitors of the Jak2-STAT3 pathway, FLLL32 and its more soluble analog, FLLL62. These compounds are structurally distinct curcumin analogs that bind selectively to the SH2 domain of STAT3 to inhibit its phosphorylation and dimerization. We hypothesized that FLLL32 and FLLL62 would induce apoptosis in RCC and melanoma cells and display specificity for the Jak2-STAT3 pathway. FLLL32 and FLLL62 could inhibit STAT3 dimerization in vitro. These compounds reduced basal STAT3 phosphorylation (pSTAT3), and induced apoptosis in four separate human RCC cell lines and in human melanoma cell lines as determined by Annexin V/PI staining. Apoptosis was also confirmed by immunoblot analysis of caspase-3 processing and PARP cleavage. Pre-treatment of RCC and melanoma cell lines with FLLL32/62 did not inhibit IFN-γ-induced pSTAT1. In contrast to FLLL32, curcumin and FLLL62 reduced downstream STAT1-mediated gene expression of IRF1 as determined by Real Time PCR. FLLL32 and FLLL62 significantly reduced secretion of VEGF from RCC cell lines in a dose-dependent manner as determined by ELISA. Finally, each of these compounds inhibited in vitro generation of myeloid-derived suppressor cells. These data support further investigation of FLLL32 and FLLL62 as lead compounds for STAT3 inhibition in RCC and melanoma.

First-in-human trial of a STAT3 decoy oligonucleotide in head and neck tumors: implications for cancer therapy.

UNLABELLED: Despite evidence implicating transcription factors, including STAT3, in oncogenesis, these proteins have been regarded as "undruggable." We developed a decoy targeting STAT3 and conducted a phase 0 trial. Expression levels of STAT3 target genes were decreased in head and neck cancers following injection with the STAT3 decoy compared with tumors receiving saline control. Decoys have not been amenable to systemic administration due to instability. To overcome this barrier, we linked the oligonucleotide strands using hexaethylene glycol spacers. This cyclic STAT3 decoy bound with high affinity to STAT3 protein, reduced cellular viability, and suppressed STAT3 target gene expression in cancer cells. Intravenous injection of the cyclic STAT3 decoy inhibited xenograft growth and downregulated STAT3 target genes in the tumors. These results provide the first demonstration of a successful strategy to inhibit tumor STAT3 signaling via systemic administration of a selective STAT3 inhibitor, thereby paving the way for broad clinical development. SIGNIFICANCE: This is the fi rst study of a STAT3-selective inhibitor in humans and the fi rst evidence that a transcription factor decoy can be modifi ed to enable systemic delivery. These findings have therapeutic implications beyond STAT3 to other "undruggable" targets in human cancers.