A549 Tumor Research Articles

Synthesis and preliminary evaluation of a 99mTc labelled deoxyglucose complex {[99mTc]DTPA-bis(DG)} as a potential SPECT based probe for tumor imaging

[99mTc]DTPA-bis(DG): a potent tumor imaging probe.

The discovery of novel indazole derivatives as tubulin colchicine site binding agents that displayed potent antitumor activity both in vitro and in vivo

Tubulin inhibitors that bind to the colchicine site are widely studied anticancer agents. In continuous our researches, we designed a series of novel indazole derivatives as microtubule-targeting agents (MTAs). The structure-activity relationships (SARs) investigations indicated that a 3,4,5-trimethoxyphenyl moiety and a methyl or methoxy substitution were preferred for the better antiproliferative activity. The indazole derivatives 3c and 3f showed noteworthy low nanomolar potency against HepG2, HCT116, SW620, HT29 and A549 tumor cells. In mechanism studies, 3c and 3f were proved to target the colchicine site, inhibited tubulin polymerization and disrupted cellular microtubule networks, arrested HCT116 cell in G2/M phase and induced cell apoptosis. In the HCT116 xenografts mouse model, 3c and 3f suppressed tumor growth by 45.3% and 58.9% at an orally dose of 25 mg/kg without causing obvious weight loss. The indazole 3f may serve as a good lead or drug candidate for colorectal cancer therapy.

Biodegradable zwitterionic polymer membrane coating endowing nanoparticles with ultra-long circulation and enhanced tumor photothermal therapy

Long blood circulation is the basic requirement of advanced drug delivery systems for tumor treatment, which leads to enhanced tumor therapeutic efficiency and reduced side effects. However, the pharmacokinetics of the current nanoparticles in vivo is still unsatisfactory, which leads to limited success to translate nanoparticles into clinical applications. Inspired by the natural cell membrane-coating strategy, a series of zwitterionic polymer membranes are firstly developed and coated onto different kinds of nanoparticles in this work. Intriguingly, the zwitterionic polymer membrane shows stronger protein adsorption resistance and reduced macrophage uptake compared with the corresponding zwitterionic polymer brush or the red blood cell (RBC) membrane, which results in longer blood circulation time and higher tumor accumulation of the coated nanoparticles. Combined with the photothermal effect of model nanoparticles, Fe3O4, zwitterionic polymer membrane-coated Fe3O4 shows enhanced photothermal therapy (PTT) efficacy on A549 tumors compared with the corresponding zwitterionic polymer brush or RBC membrane-coated Fe3O4. Notably, Fe3O4 coated by carboxybetaine-based biomimic membranes exhibits the ultra-long blood circulation (t1/2 = 96.0 h) and strongest PTT efficacy compared with those coated by phosphorylcholine-based or sulfobetaine-based biomimic membranes. In addition, the zwitterionic biomimic membrane exhibits rapid glutathione-triggered degradation with the products of low molecular weight (<2000 g mol−1). Therefore, the biodegradable zwitterionic biomimic membrane coating offers a universal platform for the design and application of long-circulating biomedical nanoparticles, which may pave the way for the clinical applications of biomedical nanoparticles in tumor therapy.

Sotetsuflavone Induces Autophagy in Non-Small Cell Lung Cancer Through Blocking PI3K/Akt/mTOR Signaling Pathway in Vivo and in Vitro.

Non-small cell lung cancer (NSCLC) is a globally scaled disease with a high incidence and high associated mortality rate. Autophagy is one of the important physiological activities that helps to control cell survival, influences the dynamics of cell death, and which plays a crucial role in the pathophysiology of NSCLC. Sotetsuflavone is a naturally derived and occurring flavonoid, and previous studies have demonstrated that sotetsuflavone possesses potential anti-cancer activities. However, whether or not sotetsuflavone induces autophagy, as well as has effects and influences cell death in NSCLC cells remains unclear. Thus, in our study, we examined and elucidated the roles and underlying mechanisms of sotetsuflavone upon the dynamics of autophagy in NSCLC in vivo and in vitro. The results indicated that sotetsuflavone was able to inhibit proliferation, migration, and invasion of NSCLC cells. Mechanistically, sotetsuflavone was able to induce apoptosis by increasing the levels of expression of cytochrome C, cleaved-caspase 3, cleaved-caspase 9, and Bax, and contrastingly decreased levels of expression of Bcl-2. In addition, we also found that decreased levels of expression of cyclin D1 and CDK4 caused arrest of the G0/G1 phases of the cell cycle. Furthermore, we also found that sotetsuflavone could induce autophagy which in turn can play a cytoprotective effect on apoptosis in NSCLC. Sotetsuflavone-induced autophagy appeared related to the blocking of the PI3K/Akt/mTOR pathway. Our in vivo study demonstrated that sotetsuflavone significantly inhibited the growth of xenograft model inoculated A549 tumor with high a degree of safety. Taken together, these findings suggest that sotetsuflavone induces autophagy in NSCLC cells through its effects upon blocking of the PI3K/Akt/mTOR signaling pathways. Our study may provide a theoretical basis for future clinical applications of sotetsuflavone and its use as a chemotherapeutic agent for treatment of NSCLC.

Microtubule inhibitors containing immunostimulatory agents promote cancer immunochemotherapy by inhibiting tubulin polymerization and tryptophan-2,3-dioxygenase

A combination therapeutic regimen via introducing tryptophan 2,3-dioxygenase inhibitors into microtubule inhibitors was performed and evaluated for their antitumor activity. Thereinto, HT2, composed of combretastatin A-4 (CA-4) and tryptophan-2,3-dioxygenase (TDO) inhibitor by a linker, displayed the most potent activity with 10-fold higher than its parent CA-4 against HepG2, A549 and HCT-116 cancer cell lines. Mechanism studies suggested that HT2 inhibited tubulin polymerization and cell migration, caused G2 phase arrest, induced apoptosis by mitochondrial mediated apoptotic pathway, concurrent depolarized the mitochondria membrane potentials and caused reactive oxygen species (ROS) production in HepG2 cells. Moreover, HT2 could enhance T-cell immune responses in vitro by releasing a TDO inhibitor to suppress TDO expression and blockade kynurenine production. As expected, HT2 could remarkably promote the antitumor activity of CA-4 in either immunocompetent H22 or immunodeficient A549 tumor xenograft models without observable toxic effects. More importantly, HT2 increased the level of splenic and tumor-infiltrated T cells and in turn effectively boosted the inhibition effect in H22 xenografted tumor growth. Collectively, this immunochemotherapeutic strategy can be applied to promote chemotherapeutic effect.

Ru(II)-Based Amino Acid Complexes Show Promise for Leukemia Treatment: Cytotoxicity and Some Light on their Mechanism of Action.

Ruthenium is attracting considerable interest as the basis for new compounds to treat diseases, and studies have shown that complexes with different structures have significant antineoplastic and antimetastatic potential against several types of tumors, including tumors resistant to cisplatin drugs. We examined the cytotoxic, genotoxic, and pro-apoptotic activities of six ruthenium complexes containing amino acid with general formulation [Ru(AA)(bipy)(dppb)]PF6, where AA = amino acid (alanine, glycine, leucine, lysine, methionine, or tryptophan); bipy = 2,2´-bipyridine; and dppb = [1,4-bis(diphenylphosphine)butane], against A549 (lung carcinoma) and K562 (chronic myelogenous leukemia) cancer cells. The results show that the ruthenium complexes tested were able to induce cytotoxicity in A549 and K562 cancer cells. Complex 1 containing alanine inhibited the cell viability of A549 and K562 tumor cells by inducing apoptosis, as evidenced by an increased number of Annexin V-positive cells and the induction of DNA damage and cell cycle arrest. Complex 1 was able to induce caspase-mediated apoptosis in K562 cells through the mitochondrial dysfunction, the upregulation of apoptotic genes, and the downregulation of Bcl2 anti-apoptotic gene. Besides being cytotoxic to K562 and A549 cells, ruthenium complex containing alanine shows low cytotoxicity and genotoxicity against non-tumor cells. These results suggest that the ruthenium (II) complex is a potential safe and efficient antineoplastic candidate for leukemia treatment.

Cytotoxic Kendomycins Containing the Carbacylic Ansa Scaffold from the Marine-Derived Verrucosispora sp. SCSIO 07399.

Three new kendomycin analogues, kendomycins B-D (1-3), were discovered from the marine-derived actinomycete Verrucosispora sp. SCSIO 07399. The structures of 1-3 were elucidated using diverse spectroscopic data analyses, X-ray crystallography, and semisynthetic derivatization. In vitro antimicrobial assays revealed that 1-3 all display good antibacterial activities against six Gram-positive bacteria with MIC values ranging from 0.5 to 8.0 μg/mL. Additionally, 1-3 were found to be moderately cytotoxic against MGC803, A549, HeLa, HepG2, MCF-7, and RKO human tumor cell lines; IC50 values ranged from 2.2 to 44 μM.

Therapeutic efficacy and imaging assessment of the HER2-targeting chemotherapy drug ZHER2:V2-pemetrexed in lung adenocarcinoma Xenografts.

Chemotherapy has always been the first therapeutic option for patients with advanced non-small cell lung cancer (NSCLC) with untreatable oncogenic mutations. However, chemotherapy has demonstrated limited success and is associated with severe side effects. This research aimed to investigate the antitumor efficacy and cytotoxic safety of the conjugate ZHER2:V2-pemetrexed, a novel targeted chemotherapeutic drug. In this context, human epidermal growth factor receptor 2 (HER2) + A549 lung xenografts were treated using ZHER2:V2-pemetrexed, pemetrexed or physiological saline. Therapeutic efficacy was monitored by single photon emission computed tomography (SPECT) imaging using the 99mTc-labeled ZHER2:V2-pemetrexed conjugate and further confirmed by performing apoptosis assays using flow cytometry analysis and hematoxylin-eosin (H&E) staining. To evaluate the expression of HER2 in tumor tissues, immunohistochemistry was performed, accompanied by quantitative analysis using flow cytometry. A toxicological evaluation was also conducted. Imaging with 99mTc-ZHER2:V2-pemetrexed demonstrated that in HER2+ A549 models, ZHER2:V2-pemetrexed showed better antineoplastic effects than pemetrexed. Compared with pemetrexed, the results from the pathological and flow cytometry analyses also revealed that ZHER2:V2-pemetrexed exhibits high antitumor activity against A549 tumors, inducing necrosis, apoptosis and cell cycle arrest. In addition, the clinical signs of toxicity in the ZHER2:V2-pemetrexed treated group were reduced compared with those in the pemetrexed treated group. These data revealed that the ZHER2:V2-pemetrexed conjugate encompasses promising targeted antitumor activity against HER2-positive lung adenocarcinoma, with reduced side effects compared with pemetrexed. Thus, the ZHER2:V2-pemetrexed conjugate may serve as a novel molecular agent with tremendous clinical breakthrough potential in the diagnosis and treatment of HER2-positive lung adenocarcinoma.

Establishment of a dual-fluorescence-traced lung cancer subcutaneous transplantation model in nude mice

Objective: To establish a nude mouse model of subcutaneous lung cancer using dual fluorescence reporting genes of luciferase (Luc) and near-infrared fluorescent protein (iRFP). Methods: The Luc and iRFP expressed lentiviral vector was constructed by Gateway method. After verified by sequencing, the lentivirus particle was prepared and infected into lung cancer A549 cells. Successfully infected A549 (mA549) cells were selected by puromycin and amplified. The expression of Luc and iRFP were observed under fluorescence microscope, and the expression of c-Met protein on the cell surface was detected by immunofluorescence. Twelve female nude mice were randomly divided into 2 groups, 6 in each group. A549 and mA549 cells were inoculated subcutaneously into the right forelimb of nude mice. The growth and fluorescence expression of the tumor were observed by in vivo imaging. The tumor formation was evaluated by hematoxylin-eosin (HE) staining and immunohistochemistry. Results: The Luc and iRFP stably expressed mA549 cell line was successfully constructed. The expressions of iRFP and Luc in mA549 cells were observed under fluorescence microscope. The results of immunofluorescence showed that c-Met protein expressed in both A549 cells and mA549 cells. The growth period of mA549 xenograft in nude mice was moderate and the tumorigenesis rate was 100%. The growth trend of mA549 cells in vivo was not significantly different from that of A549 cells (P>0.05). HE staining and immunohistochemistry results showed that the tumor issues displayed typical histopathological features of tumor. Immunohistochemistry results showed that both A549 and mA549 tumors expressed c-Met protein. Conclusion: A stable, real-time monitoring model of iRFP-Luc-A549 lung cancer cell xenograft in nude mice was successfully constructed.

BRC-mediated RNAi targeting of USE1 inhibits tumor growth in vitro and in vivo

USE1 has been demonstrated to play crucial roles in the development and progression of human lung cancer. However, the antitumor efficacy of RNA interference (RNAi) targeting of USE1 has not yet been evaluated as a possible clinical application. We here synthesized USE1 targeting bubbled RNA-based cargo (BRC) composed of densely packed multimeric pre-siRNAs with specific Dicer cleavage sites to enable efficient siRNA release upon entry to target cells. The physical entanglement and continuous networking of RNAs via hybridization during enzymatic replication serve as a driving force for the self-assembly of BRCs. These molecules effectively suppressed the transcription of their target genes, leading to tumor growth suppression in vitro and in vivo. Moreover, their repeated intravenous administration efficiently inhibited the growth of A549 tumor xenografts. Based on these findings of a reduced cancer cell viability following a USE1 knockdown, we further explored cell cycle arrest and apoptosis pathways. The observed tumor cell growth suppression was found to be controlled by cell cycle arrest and apoptosis signals induced by the USE1 reduction. These results suggest that USE1 BRCs may have future clinical applications as an RNAi-based cancer therapy.

A Pretargeted Imaging Strategy for Immune Checkpoint Ligand PD-L1 Expression in Tumor Based on Bioorthogonal Diels-Alder Click Chemistry.

The use of antibodies as tracers requires labeling with isotopes with long half-lives due to their slow pharmacokinetics, which creates prohibitively high radiation dose to non-target organs. Pretargeted methodology could avoid the high radiation exposure due to the slow pharmacokinetics of antibodies. In this investigation, we reported the development of a novel pretargeted single photon emission computed tomography (SPECT) imaging strategy (atezolizumab-TCO/[99mTc]HYNIC-PEG11-Tz) for evaluating immune checkpoint ligand PD-L1 expression in tumor based on bioorthogonal Diels-Alder click chemistry. The radioligand [99mTc]HYNIC-PEG11-Tz was achieved by the synthesis of a 6-hydrazinonicotinc acid (HYNIC) modified 1,2,4,5-tetrazine (Tz) and subsequently radiolabeled with technetium-99m (Tc-99m). The stability of [99mTc]HYNIC-PEG11-Tz was evaluated in vitro, and its blood pharmacokinetic test was performed in vivo. Atezolizumab was modified with trans-cyclooctene (TCO). The [99mTc]HYNIC-PEG11-Tz and atezolizumab-TCO interaction was tested in vitro. Pretargeted H1975 cell immunoreactivity binding and saturation binding assays were evaluated. Pretargeted biodistribution and SPECT imaging experiments were performed in H1975 and A549 tumor-bearing modal mice to evaluate the PD-L1 expression level. [99mTc]HYNIC-PEG11-Tz was successfully radiosynthesized with a specific activity of 9.25MBq/μg and a radiochemical purity above 95% as confirmed by reversed-phase HPLC (RP-HPLC). [99mTc]HYNIC-PEG11-Tz showed favorable stability in NS, PBS, and FBS and rapid blood clearance in mice. The atezolizumab was modified with TCO-NHS ester to produce a conjugate with an average 6.4 TCO moieties as confirmed by liquid chromatograph-mass spectrometer (LC-MS). Size exclusion HPLC revealed almost complete reaction between atezolizumab-TCO and [99mTc]HYNIC-PEG11-Tz in vitro, with the 1:1 Tz-to-mAb reaction providing a conversion yield of 88.65 ± 1.22%. Pretargeted cell immunoreactivity binding and saturation binding assays showed high affinity to H1975 cells. After allowing 48h for accumulation of atezolizumab-TCO in H1975 tumor, pretargeted in vivo biodistribution revealed high uptake of the radiotracer in the tumor with a tumor-to-muscle ratio of 27.51 and tumor-to-blood ratio of 1.91. Pretargeted SPECT imaging delineated the H1975 tumor clearly. Pretargeted biodistribution and SPECT imaging in control groups demonstrated a significantly reduced tracer accumulation in the A549 tumor. We have developed a HYNIC-modified Tz derivative, and the HYNIC-PEG11-Tz was labeled with Tc-99m with a high specific activity and radiochemical purity. [99mTc]HYNIC-PEG11-Tz reacted rapidly and almost completely towards atezolizumab-TCO in vitro with the 1:1 Tz-to-mAb reaction. SPECT imaging using the pretargeted strategy (atezolizumab-TCO/[99mTc]HYNIC-PEG11-Tz) demonstrated high-contrast images for high PD-L1 expression H1975 tumor and a low background accumulation of the probe. The pretargeted imaging strategy is a powerful tool for evaluating PD-L1 expression in xenograft mice tumor models and a potential candidate for translational clinical application.

AVM0703, a New Treatment Option for Lymphoma Patients

AVM0703 is a new treatment option for lymphoma patients that can eliminate or reduce the dose of standard chemotherapy in the overall treatment plan. Radiation and chemotherapy have dramatically improved survival for patients with cancer. However, the American Cancer Society has reported that chemotherapy and radiation increase the chances of secondary cancers. In fact, the report states that chemotherapy is known to be a higher risk factor than radiation in causing leukemia. The need to decrease chemotherapy administration in young adults and pediatric populations becomes even more essential considering the risk for secondary cancers. Therefore, there is an urgent need for new therapies that are as efficacious as chemotherapy and are without the harmful side effects. AVM0703 is a repurposed small molecule that has significantly extended survival in a mouse model with aggressive B cell lymphoma (A20 mouse model). In addition to being a standalone treatment, AVM0703 can also be administered as a preconditioning agent before CART cell infusion. Two FDA approved breakthrough therapies, Kymriah and Yescarta are not yet available for 33% of patients who are frail and elderly, as they are too weak to undergo the required chemotherapy preconditioning. AVM0703 can have the same preconditioning effect as chemotherapy without the toxic side effects of chemo while sparing red blood cells, stem cells and platelets. AVM0703 demonstrated a significant improvement of the effect of CART cells in a mouse model of melanoma (data not shown). Preconditioning with AVM0703 before CART administration will allow frail and elderly patients access to FDA approved cell therapy treatments. To demonstrate the efficacy of AVM0703 in a lymphoma model, A20 tumor cells were inoculated subcutaneously into the right flank in a cohort of BALB/c mice. When the tumors reached ~ 100mm3, the mice were randomized into two cohorts, control and AVM0703-treated. The control group were vehicle-treated while AVM0703-treated group were administered the active drug on day 7, 10, 17, 23, 24, 28 and 35. Tumor volumes and body weights were measured thrice weekly. Overall the treatment was very well tolerated with no treatment related deaths or toxicity observed. Dramatic body weight loss defined as greater than 20 % decrease from baseline is a frequent concern with chemo treatment, however, it was not observed in any AVM0703-treated mice. The median survival time for the control group was 16 days where as the AVM0703-treated group had a median survival time of 34 days. Therefore, this data suggests that AVM0703 treatment almost doubled the survival time of mice bearing A20 tumors (Figure 1), a fast growing B cell lymphoma model. Most interestingly, when the data was compared to the CHOP regimen, a combination of 4 therapies in the same A20 model, the efficacy results were better than 1 cycle CHOP without the extremely toxic effects observed with CHOP cycles (Figure 2). As mentioned previously AVM0703 is a repurposed molecule with decades of clinical information available on safety and toxicity, allowing a rapid clinical development program. AVM0703 is a novel high-volume formulation with a target dose that is 25 times what is used currently. It has a unique mechanism of action targeting only cancer cells, lymphocytes and monocytes while sparing platelets, RBCs and stem cells. Due to its unique profile, AVM0703 can replace chemotherapy and reduce the financial and physical toxicities associated with it. AVM0703 presents a new treatment option for lymphoma patients that is safe and effective. Disclosures No relevant conflicts of interest to declare.

Discovery of an Oleanolic Acid/Hederagenin-Nitric Oxide Donor Hybrid as an EGFR Tyrosine Kinase Inhibitor for Non-Small-Cell Lung Cancer.

Natural triterpenoids, such as oleanolic acid (OA) and hederagenin, display anti-lung cancer effects, and nitric oxide (NO) is associated with some oncogenic signaling pathways. Accordingly, 17 OA/hederagenin-NO donor hybrids were designed, synthesized, and evaluated against tumor cells. The most potent compound, 13, significantly inhibited the proliferation of five tumor cell lines (IC50 4.6-5.2 μM), while hederagenin inhibited the growth of only A549 tumor cells (IC50 > 10 μM). Furthermore, compound 13 showed stronger inhibitory effects on EGFR-LTC kinase activity (IC50 0.01 μM) than hederagenin (IC50 > 20 μM) and inhibited the proliferation of gefitinib-resistant H1975 (IC50 8.1 μM) and osimertinib-resistant H1975-LTC (IC50 7.6 μM) non-small-cell lung cancer (NSCLC) cells. Moreover, compound 13 produced the most NO in H1975 tumor cells, which indicated that NO may play a synergistic role. Collectively, compound 13, a novel hederagenin-NO donor hybrid with a different chemical structure from those of the current FDA-approved EGFR-targeted anti-NSCLC drugs, may be a promising lead compound for the treatment of NSCLC expressing gefitinib-resistant EGFR with a T790 M mutation or osimertinib-resistant EGFR-LTC with an L858R/T790M/C797S mutation. This work should shed light on the discovery of new anti-NSCLC drugs targeting EGFR from natural products.

Glibenclamide Targets Sulfonylurea Receptor 1 to Inhibit p70S6K Activity and Upregulate KLF4 Expression to Suppress Non-Small Cell Lung Carcinoma.

Sulfonylurea receptor 1 (SUR1) is the regulatory subunit of ATP-sensitive potassium channels (KATP channels) and the receptor of antidiabetic drugs, such as glibenclamide, which induce insulin secretion in pancreatic β cells. However, the expression and role of SUR1 in cancer are unknown. In this study, we found that SUR1 expression was elevated in human non-small cell lung carcinoma (NSCLC) tissues and cell lines. SUR1 silencing suppressed the growth of NSCLC cells, while SUR1 overexpression promoted cell growth. Targeting SUR1 with glibenclamide suppressed cell growth, cell-cycle progression, epithelial-mesenchymal transition (EMT), and cell migration. Moreover, SUR1 directly interacted with p70S6K and upregulated p70S6K phosphorylation and activity. In addition, glibenclamide inhibited p70S6K, and overexpression of p70S6K partially reversed the growth-inhibiting effect of glibenclamide. Furthermore, glibenclamide upregulated the expression of the tumor suppressor Krüppel-like factor 4 (KLF4), and silencing KLF4 partially reversed the inhibitory effect of glibenclamide on cell growth, EMT, and migration. We found that SUR1 targeted p70S6K to downregulate KLF4 expression by enhancing DNA-methyltransferase 1-mediated methylation of the KLF4 promoter. Finally, in xenograft mouse models, SUR1 expression silencing or glibenclamide treatment inhibited the growth of A549 tumors, downregulated p70S6K activity, and upregulated KLF4 expression. These findings suggested that SUR1 expression was elevated in some NSCLC tissues and functioned as a tumor enhancer. Targeting SUR1 with glibenclamide inhibited NSCLC through downregulation of p70S6K activity and subsequent upregulation of the expression of the tumor suppressor gene KLF4 SUR1 can be developed as a new target for cancer therapy and glibenclamide has potential anticancer effects.

Antiproliferative and genotoxic potential of xanthen-3-one derivatives.

Twelve previously synthesized, biologically active 2,6,7-trihydroxyxanthen-3-one derivatives were evaluated in vitro for antiproliferative activity. Compounds were screened against HeLa, SW620, HepG2 and A549 tumor cell lines. Compound with the trifluormethyl group on C-4' position of the phenyl ring showed the best inhibitory activity towards HeLa and A549 tumor cells with IC50 of 0.7 and 4.1 µmol L-1, resp. Compound with chlorine and fluorine substituents on aryl ring showed the best antiproliferative activity against SW620 with IC50 of 4.1 µmol L-1 and against HepG2 tumor cell line with IC50 of 4.2 µmol L-1. Analyses of cytotoxic and genotoxic potential of the trifluormethyl derivative were performed with cytokinesis-block micronucleus cytome assay in human lymphocyte culture and revealed no genotoxic and cytotoxic effects. The most potent compounds were subjected to molecular docking simulations in order to analyse bindings to molecular targets and, at the same time, further support the results of experimental cytotoxic tests. Docking studies showed sites of importance in forming hydrogen bonds of the most potent compounds with targets of interest.

PTC-209 Anti-Cancer Effects Involved the Inhibition of STAT3 Phosphorylation.

Introduction: Lung, breast, and colorectal cancers are the leading causes of cancer-related deaths despite many therapeutic options, including targeted therapy and immunotherapies. Methods: Here, we investigated the impact of PTC-209, a small-molecule Bmi-1 inhibitor, on human cancer cell viability alone and in combination with anticancer drugs, namely, cisplatin, oxaliplatin, 5-fluorouracil, camptothecin, and Frondoside-A and its impact on cellular migration and colony growth in vitro and on tumor growth in ovo. Results: We demonstrate that PTC-209 causes a concentration- and time-dependent decrease in the cellular viability of lung cancer cells (LNM35 and A549), breast cancer cells (MDA-MB-231 and T47D), and colon cancer cells (HT-29, HCT8/S11, and HCT-116). Similarly, treatment with PTC-209 significantly decreased the growth of LNM35, A549, MDA-MB-231, and HT-29 clones and colonies in vitro and LNM35 and A549 tumor growth in the in ovo tumor xenograft model. PTC-209 at the non-toxic concentrations significantly reduced the migration of lung (LNM35 and A549) and breast (MDA-MB-231) cancer cells. Moreover, we show that PTC-209, at a concentration of 1 μM, enhances the anti-cancer effects of Frondoside-A in lung, breast, and colon cancer cells, as well as the effect camptothecin in breast cancer cells and the effect of cisplatin in lung cancer cells in vitro. However, PTC-209 failed to enhance the anti-cancer effects of oxaliplatin and 5-fluorouracil in colon cancer cells. Treatment of lung, breast, and colon cancer cells with PTC-209 (1 and 2.5 μM) for 48 h showed no caspase-3 activation, but a decrease in the cell number below the seeding level suggests that PTC-209 reduces cellular viability probably through inhibition of cell proliferation and induction of cell death via a caspase-3–independent mechanism. Molecular mechanism analysis revealed that PTC-209 significantly inhibited the STAT3 phosphorylation by decreasing the expression level of gp130 as early as 30 min post-treatment. Conclusion: Our findings identify PTC-209 as a promising anticancer agent for the treatment of solid tumors either alone and/or in combination with the standard cytotoxic drugs cisplatin and camptothecin and the natural product Frondoside-A.

Paris saponin VII extracted from Trillium tschonoskii induces autophagy and apoptosis in NSCLC cells.

Trillium tschonoskii Maxim, a perennial herb of the Trilliaceae, has been widely used to treat inflammation, hypertension and cancer. We investigated Paris saponin VII's (PS VII), isolated from Trillium tschonoskii Maxim, function in mediating autophagy and apoptosis in NSCLC cells. We treated various NSCLC cells with different concentrations of PS Ⅶ and then measure the cell apoptosis by using flow cytometry assays and western blot. Autophagy were investigated by using western blot, transmission electron microscopy and immunofluorescence analysis. We also use a xenograft model of nude mice to measure the effect of PS Ⅶ in vivo. Treatment with PS Ⅶ significantly inhibit NSCLC cell growth, especially for A549 (IC50 = 1.53 μM). Moreover, PS VII induces caspase-dependent apoptosis and autophagy through AMPK-ULK1 pathway. After blocking autophagy by 3-methyladenine (3-MA), PS VII induced cell death was significantly increased. In vivo, the co-treatment with PS VII and 3-MA dramatically inhibited A549 tumor growth in immune deficient mice and has similar inhibition rates as cisplatin group. Our results suggest that a combination of PS VII and autophagy inhibitor may be a potential anticancer strategy in the NSCLC therapy.

Steroidal constituents from Helleborus thibetanus and their cytotoxicities.

Thibetanosides E-H (1-4), four new steroidal constituents including three rare sulfonates (2-4), were isolated from the roots and rhizomes of Helleborus thibetanus, together with nine known steroidal compounds (5-13). Their structures were elucidated by detailed spectroscopic analysis, including 1D and 2D NMR techniques and chemical evidence. In this study, compounds 2-13 were evaluated for their cytotoxic activities against HCT116, A549 and HepG2 tumor cell lines in vitro. Among them, compound 8 (thibetanoside C) showed cytotoxicities against A549 cells(IC50 39.6 ± 1.9 μmol·L-1) and HepG2 cells(IC50 41.5 ± 1.1 μmol·L-1), respectively. Compound 9 (23S, 24S)-24-[(O-β-D-fucopyranosyl)oxy]-3β, 23-dihydroxy-spirosta-5, 25(27)-diene-1β-ylO-(4-O-acetyl- α-L-rhamnopyranosyl)-(1→2)-O-[β-D-xylopyranosyl-(1→3)]-α-L-arabinopyranoside) showed cytotoxicity against HCT116 cells(IC50 33.6 ± 2.1 μmol·L-1).

Preclinical evaluation of a dual sstr2 and integrin αvβ3-targeted heterodimer [68Ga]-NOTA-3PEG4-TATE-RGD

PurposeMultiple receptors are co-expressed in many types of cancers. Octreotate (TATE) and Arg-Gly-Asp (RGD) peptides target somatostatin receptor 2 (sstr2) and integrin αvβ3, respectively. We developed and synthesized a heterodimer NOTA-3PEG4-TATE-RGD (3PTATE-RGD) and aimed to investigate its characteristics for dual-targeting sstr2 and integrin αvβ3. MethodsTATE and RGD peptides and 1,4,7-triazacylononane-N’,N’’,N’’’-triacetic acid (NOTA) were linked through a glutamate and polyethylene glycol (PEG) linker, then 3PTATE-RGD was labeled with 68Ga ion. Receptor-binding characteristics and tumor-targeting efficacy were tested in vitro and in vivo using H69 and A549 lung cancer cell lines and tumor-bearing mice models. Results[68Ga]-3PTATE-RGD had comparable sstr2 and integrin αvβ3-binding affinity with monomeric TATE and RGD in cell uptake and PET imaging study, respectively. In the competition study, H69 and A549 tumor uptake of [68Ga]-3PTATE-RGD was completed inhibited in the presence of an excess amount of unlabeled TATE or RGD, respectively. The blocked level didn’t grow when both of TATE and RGD mixture was co-injected with [68Ga]-3PTATE-RGD. The pharmacokinetics of [68Ga]-3PTATE-RGD is comparable with [68Ga]-TATE and [68Ga]-RGD, resulting in a larger application. Conclusion[68Ga]-3PTATE-RGD showed improved and wider tumor-targeting efficacy compared with monomeric TATE and RGD peptides, which warrants its further investigation in detection both of sstr2 and integrin αvβ3-related carcinomas.

Effect of Ionizing Radiation on Human EA.hy926 Endothelial Cells under Inflammatory Conditions and Their Interactions with A549 Tumour Cells.

Purpose Most tumours are characterized by an inflammatory microenvironment, and correlations between inflammation and cancer progression have been shown. Endothelial cells (ECs), as part of the tumour microenvironment, play a crucial role in inflammatory processes as well as in angiogenesis and could be critical targets of cancer therapy like irradiation. Therefore, in the present study we investigated the effect of ionizing radiation on endothelial cells under inflammatory conditions and their interactions with tumour cells. Methods Nonactivated and TNF-α treatment-activated human EC EA.hy926 were irradiated with doses between 0.1 Gy and 6 Gy with a linear accelerator. Using a multiplex assay, the accumulation of various chemokines (IL-8, MCP-1, E-selectin, and P-selectin) and soluble adhesion molecules (sICAM-1 and VCAM-1) as well as protein values of the vascular endothelial growth factor (VEGF) was measured in the supernatant at different time points. The adhesion capability of irradiated and nonirradiated A549 tumour cells to EA.hy926 cells was measured using flow cytometry, and the migration of tumour cells was investigated with a scratch motility assay. Results In contrast to unirradiated cells, IR of ECs resulted in a modified release of chemokines IL-8 and MCP-1 as well as the adhesion molecules sICAM-1 and VCAM-1 in the EC, whereas concentrations of E-selectin and P-selectin as well as VEGF were not influenced. IR always affected the adhesion capability of tumour cells to ECs with the effect dependent on the IR-treated cell type. TNF-α treatment generally increased adhesion ability of the tumour cells. Tumour cell migration was clearly inhibited after IR. This inhibitory effect was eliminated for radiation doses from 0.5 to 2 Gy when, additionally, an inflammatory environment was predominant. Conclusions Our results support past findings suggesting that ECs, as part of the inflammatory microenvironment of tumours, are important regulators of the actual tumour response to radiation therapy.