Allshine Chen

Nanosomes carrying doxorubicin exhibit potent anticancer activity against human lung cancer cells

Successful chemotherapeutic intervention for management of lung cancer requires an efficient drug delivery system. Gold nanoparticles (GNPs) can incorporate various therapeutics; however, GNPs have limitations as drug carriers. Nano-sized cellular vesicles like exosomes (Exo) can ferry GNP-therapeutic complexes without causing any particle aggregation or immune response. In the present study, we describe the development and testing of a novel Exo-GNP-based therapeutic delivery system -‘nanosomes’- for lung cancer therapy. This system consists of GNPs conjugated to anticancer drug doxorubicin (Dox) by a pH-cleavable bond that is physically loaded onto the exosomes (Exo-GNP-Dox). The therapeutic efficacy of Dox in nanosomes was assessed in H1299 and A549 non-small cell lung cancer cells, normal MRC9 lung fibroblasts, and Dox-sensitive human coronary artery smooth muscle cells (HCASM). The enhanced rate of drug release under acidic conditions, successful uptake of the nanosomes by the recipient cells and the cell viability assays demonstrated that nanosomes exhibit preferential cytotoxicity towards cancer cells and have minimal activity on non-cancerous cells. Finally, the underlying mechanism of cytotoxicity involved ROS-mediated DNA damage. Results from this study mark the establishment of an amenable drug delivery vehicle and highlight the advantages of a natural drug carrier that demonstrates reduced cellular toxicity and efficient delivery of therapeutics to cancer cells.

HuR-targeted nanotherapy in combination with AMD3100 suppresses CXCR4 expression, cell growth, migration and invasion in lung cancer

The CXCR4 chemokine receptor has an important role in cancer cell metastasis. The CXCR4 antagonist, AMD3100, has limited efficacy in controlling metastasis. HuR, an RNA-binding protein, regulates CXCR4 in cancer cells. We therefore investigated whether targeting HuR using a siRNA-based nanoparticle plus AMD3100 would suppress CXCR4 and inhibit lung cancer metastasis. We treated human H1299 lung cancer cells with HuR-specific siRNA contained in a folate-targeted lipid nanoparticle (HuR-FNP) plus AMD3100, and compared this with AMD3100 alone, HuR-FNP alone and no treatment. HuR-FNP plus AMD3100 treatment produced a G1 phase cell cycle arrest and reduced cell viability above and beyond the effects of AMD3100 alone. HuR and CXCR4 mRNA and protein expression levels were markedly reduced in all treatment groups. Phosphorylated (p) AKTS473 protein was also reduced. P27 protein expression increased with HuR-FNP and combination treatment. Promoter-based reporter studies showed that the combination inhibited CXCR4 promoter activity more than did either treatment alone. Cell migration and invasion was significantly reduced with all treatments; the combination provided the most inhibition. Reduced matrix metalloprotease (MMP)-2 and -9 expression was associated with reduced invasion in all treatment groups. Thus, we found that combined HuR and CXCR4 targeting effectively controlled lung cancer metastasis.

Chemodrug delivery using integrin-targeted PLGA-Chitosan nanoparticle for lung cancer therapy

In this study, we report the efficacy of RGD (arginine-glycine-aspartic acid) peptide-modified polylactic acid-co-glycolic acid (PLGA)-Chitosan nanoparticle (CSNP) for integrin αvβ3 receptor targeted paclitaxel (PTX) delivery in lung cancer cells and its impact on normal cells. RGD peptide-modified chitosan was synthesized and then coated onto PTX-PLGA nanoparticles prepared by emulsion-solvent evaporation. PTX-PLGA-CSNP-RGD displayed favorable physicochemical properties for a targeted drug delivery system. The PTX-PLGA-CSNP-RGD system showed increased uptake via integrin receptor mediated endocytosis, triggered enhanced apoptosis, and induced G2/M cell cycle arrest and more overall cytotoxicity than its non-targeted counterpart in cancer cells. PTX-PLGA-CSNP-RGD showed less toxicity in lung fibroblasts than in cancer cells, may be attributed to low drug sensitivity, nevertheless the study invited close attention to their transient overexpression of integrin αvβ3 and cautioned against corresponding uptake of toxic drugs, if any at all. Whereas, normal human bronchial epithelial (NHBE) cells with poor integrin αvβ3 expression showed negligible toxicity to PTX-PLGA-CSNP-RGD, at equivalent drug concentrations used in cancer cells. Further, the nanoparticle demonstrated its capacity in targeted delivery of Cisplatin (CDDP), a drug having physicochemical properties different to PTX. Taken together, our study demonstrates that PLGA-CSNP-RGD is a promising nanoplatform for integrin targeted chemotherapeutic delivery to lung cancer.

Tumor-targeted nanoparticle delivery of HuR siRNA inhibits lung tumor growth in vitro and in vivo by disrupting the oncogenic activity of the RNA-binding protein HuR

Selective downregulation of the human antigen R (HuR) protein by siRNA may provide a powerful approach for treating lung cancer. To this end, we investigated the efficacy of transferrin receptor-targeted liposomal nanoparticle-based HuR siRNA (HuR-TfNP) therapy and compared with control siRNA (C)-TfNP therapy both, in vitro and in vivo using lung cancer models. In vitro studies showed HuR-TfNP, but not C-TfNP, efficiently downregulated HuR and HuR-regulated proteins in A549, and HCC827 lung cancer cells, resulting in reduced cell viability, inhibition of cell migration and invasion, and induction of G1 cell-cycle arrest culminating in apoptosis. However, HuR-TfNP activity in normal MRC-9 lung fibroblasts was negligible. In vivo biodistribution study demonstrated that fluorescently labeled HuR-siRNA or ICG dye–loaded TfNP localized in tumor tissues. Efficacy studies showed intratumoral or intravenous administration of HuR-TfNP significantly inhibited A549 (>55% inhibition) and HCC827 (>45% inhibition) subcutaneous tumor growth compared with C-TfNP. Furthermore, HuR-TfNP treatment reduced HuR, Ki67, and CD31 expression and increased caspase-9 and PARP cleavage and TUNEL-positive staining indicative of apoptotic cell death in tumor tissues compared with C-TfNP treatment. The antitumor activity of HuR-TfNP was also observed in an A549-luc lung metastatic model, as significantly fewer tumor nodules (9.5 ± 3.1; P < 0.001; 88% inhibition) were observed in HuR-TfNP–treated group compared with the C-TfNP–treated group (77.7 ± 20.1). Significant reduction in HuR, Ki67, and CD31 expression was also observed in the tumor tissues of HuR-TfNP-treatment compared with C-TfNP treatment. Our findings highlight HuR-TfNP as a promising nanotherapeutic system for lung cancer treatment. Mol Cancer Ther; 16(8); 1470–86. ©2017 AACR.

HuR-targeted small molecule inhibitor exhibits cytotoxicity towards human lung cancer cells

Human antigen (Hu) R is an RNA-binding protein whose overexpression in human cancer correlates with aggressive disease, drug resistance, and poor prognosis. HuR inhibition has profound anticancer activity. Pharmacologic inhibitors can overcome the limitations of genetic inhibition. In this study, we examined the antitumor activity of CMLD-2, a small-molecule inhibitor directed against HuR, using non-small cell lung cancer (NSCLC) as a model. CMLD-2 efficacy was tested in vitro using H1299, A549, HCC827, and H1975 NSCLC cells and MRC-9 and CCD-16 normal human fibroblasts. Treatment of NSCLC cells with CMLD-2 produced dose-dependent cytotoxicity, caused a G1 phase cell-cycle arrest and induced apoptosis. CMLD-2 decreased HuR mRNA and the mRNAs of HuR-regulated proteins (Bcl2 and p27) in tumor cells. Additionally, reduction in the expression of HuR, Bcl2, cyclin E, and Bcl-XL with increased expression of Bax and p27 in CMLD-2-treated NSCLC cells were observed. CMLD-2-treated normal cells, HuR-regulated mRNAs and proteins albeit showed some reduction were less compared to tumor cells. Finally, CMLD-2 treatment resulted in greater mitochondrial perturbation, activation of caspase-9 and -3 and cleavage of PARP in tumor cells compared to normal cells. Our proof-of concept study results demonstrate CMLD-2 represents a promising HuR-targeted therapeutic class that with further development could lead to advanced preclinical studied and ultimately for lung cancer treatment.

The Impact on Endoscopic Resource Utilization After a Targeted Intervention for Cost-Minimization of EGD and Colonoscopy

Objectives:The need to define the cost of endoscopic procedures becomes increasingly important in an era of providing low-cost, high-quality care. We examined the impact of informing endoscopists of the cost of accessories and pathology specimens as a cost-minimization strategy.Methods:We conducted a prospective observational cohort study of therapeutic outpatient esophagogastroduodenoscopy (EGD) and colonoscopy. During the pre-intervention phase (phase 1), the endoscopists were not briefed on the cost of accessories or pathology specimens obtained during the procedure. During a 3-week intervention phase and the post-intervention phase (phase 2) endoscopists were informed of the dollar value of accessories and pathology specimens after the completion of all procedures. In all cases the institutional costs (not charges) were used. The endoscopists were blinded to their observation.Results:A total of 969 EGD, colonoscopy, and EGD+colonoscopy performed by 6 endoscopists were reviewed, 456 procedures in phase 1 and 513 procedures in phase 2. There was no significant difference between phases 1 and 2 in total device and pathology cost in dollars (188.8±151.4 vs. 188.9±151.8, P=0.99), total device cost (36.2±107.9 vs. 39.0±95.96, P=0.67) and total pathology cost (152.6±101.3 vs. 149.9±112.5, P=0.70). There was not a significant difference in total device and pathology cost when examined by specific procedures performed, or for any of the endoscopists between phases 1 and 2.Conclusions:Making endoscopists more cost conscious by informing them of the costs of each procedure during EGD and colonoscopy does not result in lower procedural costs. Analysis of cost-minimization strategies involving procedures in other health-care settings and procedures using high-cost accessories are warranted.

Chemo-biologic combinatorial drug delivery using folate receptor-targeted dendrimer nanoparticles for lung cancer treatment

Co-administration of functionally distinct anti-cancer agents has emerged as an efficient strategy in lung cancer treatment. However, a specially designed drug delivery system is required to co-encapsulate functionally different agents, such as a combination of siRNA and chemotherapy, for targeted delivery. We developed a folic acid (FA)-conjugated polyamidoamine dendrimer (Den)-based nanoparticle (NP) system for co-delivery of siRNA against HuR mRNA (HuR siRNA) and cis-diamine platinum (CDDP) to folate receptor-α (FRA) -overexpressing H1299 lung cancer cells. The co-delivery of HuR siRNA and CDDP using the FRA-targeted NP had a significantly greater therapeutic effect than did individual therapeutics. Further, the FRA-targeted NP exhibited improved cytotoxicity compared to non-targeted NP against lung cancer cells. Finally, the NP showed negligible toxicity towards normal MRC9 lung fibroblast cells. Thus, the present study demonstrates FRA-targeted Den nanoparticle system as a suitable carrier for targeted co-delivery of siRNA and chemotherapy agents in lung cancer cells.

Response to Kane et al.

To the Editor: We read with great interest the study by Kaitha et al. ( 1 ) in regard to the lack of reduction of resource utilization during endoscopic procedures. In an eff ort to manage impractical expenses in our high-volume endoscopy practice, we developed a multi-faceted education program aimed at reducing costs associated with endoscopic accessories. Th e fi rst part was to educate physicians directly on the frequency of utilization of specifi c non-superior high-cost equipment (e.g., specialty snares, wires), as well as the appropriate indications for prophylactic clip placement post polypectomy. Th e second part was to color-code accessories in the endoscopy rooms with green/yellow/ red stickers, refl ecting their relative costs. Within a year, we noted a decrease in utilization of high-cost snares from 392 to 334 despite an increase in the overall volume of snares used. We also reported a signifi cant decrease in the number of clips used ( 2 ). We believe a multi-faceted approach directly educating endoscopists to avoid the empiric use of devices and to utilize equally eff ective and optimally priced items, along with longer follow-up time, led to the success of our program.

489. Tumor-Targeted Hursirna-Nanoparticle Delivery Inhibits Lung Tumor Growth In Vitro and In Vivo

HuR, an mRNA binding protein regulates the stability of many oncoproteins associated with cell survival, proliferation, migration and angiogenesis. HuR overexpression is a marker for poor prognosis in patients diagnosed with cancer of lung, ovary, breast and colon. We hypothesized that the silencing of HuR using small interfering RNA (siRNA) could be a promising approach for lung cancer therapy. To test our hypothesis, we developed a tumor-targeted nanoparticle (NP) system that is targeted to transferrin receptor (TfR) for delivering HuRsiRNA (HuR-TfNP) in human lung cancer cells. Human lung cancer cells (A549, HCC827) and normal lung fibroblast (MRC-9) cell lines expressing varying levels of TfR were used in the present study. TfR expression was highest in A549, moderate in HCC827, and low to undetectable in MRC9 cells. In vitro studies demonstrated enhanced uptake of Tf-NP (51%) in TfR overexpressing A549 cells, compared to the non-targeted NP. Specificity studies using desferrioxamine (DFO; 100 µM), a stimulator of TfR, showed a two-fold increased uptake of Tf-NP whereas blocking TfR with exogenous transferrin (1 µg/well) reduced the uptake by 3 fold in A549 cells. Further, HuR-TfNP treatment reduced HuR expression and significantly suppressed cell proliferation at 24h and 48h compared to control siRNA containing NP (C-Tf-NP) in tumor cells but not in normal cells. Greatest inhibition was observed in A549 cells (23% and 30% inhibition at 24 and 48 h respectively) compared to 15% and 25% in HCC827. In MRC-9 cells, only 4% inhibition was observed. HuR-TfNP induced G1 cell-cycle arrest in tumor cells that correlated with marked reduction in Cyclin D1, and Cyclin E protein expression. Further, tumor cell migration and invasion was significantly inhibited in HuR-TfNP treated tumor cells compared to C-TfNP treatment (p<0.001). In-vivo, Tf-NP bio-distribution studies using indocyanine green (ICG) showed accumulation of the NP in tumor tissues over time with maximum accumulation at 24 h post NP injection. Efficacy studies in A549 tumor model demonstrated that systemic administration of HuR-TfNP significantly inhibited growth of both subcutaneous tumor growth and experimental lung metastasis compared to C-TfNP treatment (P<0.05). Further, tumor growth delay was sustained over 70 days when compared to control groups. A marked reduction in the expression of HuR and HuR-regulated oncoproteins (Bcl2, Cyclin D1 and Cyclin E) with a concomitant increase in p27 expression was observed in HuR-TfNP-treated tumors compared to control tumors. Our study results demonstrate HuR-TfNP therapy suppressed lung tumor growth both in vitro and in vivo and is therapeutic target for lung cancer treatment.

Abstract 3738: IL-24 modulates the high mobility group (HMG) A1/miR222 /AKT signaling in lung cancer cells

Background: High mobility group A1 (HMGA1), a member of the non-histone chromosomal proteins and commonly referred to as architectural transcription factor, regulates transcription of various genes involved in cell growth and survival. Overexpression of HMGA1 has been shown to be associated with tumor progression and metastasis in several cancers, including human lung cancer. A recent study demonstrated that HMGA1 activates AKT function by reducing the activity of the protein phosphatase, phosphatase 2A subunitB (PPPR2A) via the oncogenic micro (mi) RNA-222. We demonstrated that interleukin (IL)-24, a novel tumor suppressor/cytokine, inhibited AKT in lung cancer cells. However, the molecular mechanism of AKT inhibition by IL-24 remains elusive. Aim: To determine the molecular mechanism of IL-24-mediated AKT inhibition involved the HMGA1/miR-222 axis. Methods: Human H1299 lung tumor cell line was stably transfected with a tetracycline-inducible plasmid vector carrying the IL-24. After the induced expression of IL-24 protein, expression levels of HMGA1 and its downstream molecular mechanisms were analyzed at the RNA and protein levels in lung cancer cell lines. The inhibitory effect of IL-24 on HMG A1/miR222 /AKT axis in the lung cancer cells is determined by RT-qPCR, western blot, reporter assay, and immunocytochemistry. Mechanistic approaches on overexpression and knockdown of HMGA1 and or miR-222 were utilized and the consequences of its inhibition/overexpression were analyzed on HMGA1/miR222 /AKT signaling axis and in vitro migration and invasion. Results: Upon induction of IL-24 expression in the H1299 lung tumor cells, we observed a marked reduction in HMGA1protein and mRNA levels. Using a mechanistic approach, we found that IL-24 reduced miR-222-3p and -5p levels, as determined by qRT-PCR. Associated with HMGA1 and miR-222 inhibition was a marked increase in PPP2R2A, with a concomitant decrease in phosphorylated AKTT308/S473 expression. SiRNA-mediated knockdown of HMGA1in combination with IL-24 significantly reduced AKT T308/S473 protein expression and greatly reduced cell migration and invasion compared with individual treatments. Further combination of IL-24 and a miR-222-3p inhibitor significantly increased PPP2R2A expression. Conclusion: Our results demonstrate for the first time that IL-24 inhibits AKT via regulating the HMGA1/miR-222 signaling node in human lung cancer cells and acts as an effective tumor suppressor. HMGA1 should present a novel target for the effective treatment of lung cancer. Citation Format: Janani Panneerselvam, Akhil Srivastava, Ranganayaki Muralidharan, Qi Wang, Wei Zheng, Lichao Zhao, Allshine Chen, Yan Zhao, Anupama Munshi, Rajagopal Ramesh. IL-24 modulates the high mobility group (HMG) A1/miR222 /AKT signaling in lung cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3738.