Multicellular Tumor Spheroid Model Research Articles

Exploration of isoxazole analogs: Synthesis, COX inhibition, anticancer screening, 3D multicellular tumor spheroids, and molecular modeling

In this study, a new series of Isoxazole-carboxamide derivatives were synthesized and characterized via HRMS, 1H-, 13CAPT-NMR, and MicroED. The findings revealed that nearly all of the synthesized derivatives exhibited potent inhibitory activities against both COX enzymes, with IC50 values ranging from 4.1 nM to 3.87 μM. Specifically, MYM1 demonstrated the highest efficacy among the compounds tested against the COX-1, displaying an IC50 value of 4.1 nM. The results showed that 5 compounds possess high COX-2 isozyme inhibitory effects with IC50 value in range 0.24–1.30 μM with COX-2 selectivity indexes (2.51–6.13), among these compounds MYM4 has the lowest IC50 value against COX-2, with selectivity index around 4. Intriguingly, this compound displayed significant antiproliferative effects against CaCo-2, Hep3B, and HeLa cancer cell lines, with IC50 values of 10.22, 4.84, and 1.57 μM, respectively, which was nearly comparable to that of doxorubicin. Compound MYM4 showed low cytotoxic activities on normal cell lines LX-2 and Hek293t with IC50 values 20.01 and 216.97 μM respectively, with safer values than doxorubicin. Furthermore, compound MYM4 was able to induce the apoptosis, suppress the colonization of both HeLa and HepG2 cells. Additionally, the induction of Reactive oxygen species (ROS) production could be the mechanism underlying the apoptotic effect and the cytotoxic activity of the compound. In the 3D multicellular tumor spheroid model, results revealed that MYM4 compound hampered the spheroid formation capacity of Hep3B and HeLa cancer cells. Moreover, the molecular docking of MYM4 compound revealed a high affinity for the COX2 enzyme, with energy scores (S) −7.45 kcal/mol, which were comparable to celecoxib (S) −8.40 kcal/mol. Collectively, these findings position MYM4 as a promising pharmacological candidate as COX inhibitor and anticancer agent.

Abstract 3204: Antitumor activity of a coencapsulated liposomal formulation of ceramides and doxorubicin in neuroblastoma models

Abstract Background: Neuroblastoma (NB) represents the most frequent and aggressive form of extracranial solid tumor of infants. Targeted therapies are severely limited by the lack of specific receptors, thus chemotherapy and radiotherapy remain the main treatment choices, which expose NB patients to systemic toxicity. Recently, we have demonstrated that cell surface Nucleolin (NCL) represents a novel cellular target for NB therapy. Methods: The cytotoxic potential of pH-sensitive nanocarriers (NC), decorated with the NCL-recognizing F3 peptide and incorporating a combination of the PI3K/Akt signaling inhibitors, C6-Ceramide (C6-Cer) or C18-ceramide (C18-Cer), and the topoisomerase II inhibitor doxorubicin (DXR) (F3-NC[C6-Cer/DXR] and F3-NC[C18-Cer/DXR], respectively), was tested in vitro on a panel of NB cell lines. Cytotoxicity was evaluated in monolayer and in multicellular tumor spheroid models, by MTS proliferation and Cell Titer Glo 3D cell viability assays, respectively. Apoptotic/necrotic cell death was investigated by Real Time-Glo Annexin VApoptosis and Necrosis assay. Results: F3-NC[C6-Cer/DXR] and F3-NC[C18-Cer/DXR] resulted significantly more effective, in term of reduction of NB cell viability, compared to the corresponding “drugs”-loaded untargeted NC formulations. Both formulations triggered apoptotic cell death, even if in a different kinetic profile. In particular, NB cells treated with F3-NC[C6-Cer/DXR] underwent apoptotic cell death earlier with respect to those treated with F3-NC[C18-Cer/DXR]. Interestingly, F3-NC[C6-Cer/DXR] exerted a significant superior cell killing effect when compared both to F3-NC[C18-Cer/DXR] and to F3-NC encapsulating only DXR, suggesting the importance of the combination treatment to enhance the antitumor effect against NB cells. Conclusion: Our preliminary findings demonstrate that the co-encapsulation and delivery of C6-Ceramide and DXR by NCL-recognizing nanoparticles exert potent antitumor effects against NB models in vitro. Ongoing in vivo experiments on clinically relevant mouse NB models (i.e. recapitulating primary tumor growth, metastases, and minimal residual disease) will allow us to define the possible use of F3-NC[C6-Cer/DXR] as an innovative therapeutic strategy for relapsed/refractory NB. Funding: AIRC IG n. 24397 to PF; CInTech (PRR) C644865576-00000005 to JNM.VB is recipient of AIRC ID 24397 contract. MBC is recipient of PD/BDE/150664/2020 (FCT) fellowship. Citation Format: Veronica Bensa, Mariana Biscaia-Caleiras, Mirco Ponzoni, Joao Nuno Moreira, Chiara Brignole, Fabio Pastorino. Antitumor activity of a coencapsulated liposomal formulation of ceramides and doxorubicin in neuroblastoma models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3204.

Abstract 6765: A patient-derived hepatocellular carcinoma multicellular spheroid platform harnessing autologous patient serum to model the tumor microenvironment and treatment response

Abstract Hepatocellular carcinoma (HCC) is the third leading and fastest rising cause of cancer-related death worldwide. The discovery and preclinical development of compounds targeting HCC is hampered by the absence of authentic tractable systems recapitulating the heterogeneity of patient HCC tumors and the tumor microenvironment (TME). Here, we established a novel, simple and robust patient-derived multicellular tumorspheroid model based on clinical HCC tumor tissues combined with the autologous patient serum. The model was robust and reproducible independently from cancer etiology and grade recapitulating key functional features of original tissue. We show that the use of autologous patient serum was essential for the TME function. The tumorspheroids comprised the main cell compartments including epithelial cancer cells as well as all major cell populations of the TME (cancer-associated fibroblasts, macrophages and T cells). Cell type proportions were variable between tumorspheroids reflecting HCC heterogeneity. Moreover, we observed differential responses to FDA HCC approved drugs (including tyrosine kinase and checkpoint inhibitors as well as VEGF-targeting agents) between donors as in patients. This patient HCC serum-tumorspheroid model provides novel opportunities for drug discovery and development as well mechanism of action studies including compounds targeting the TME. In conclusion, this HCC serum-tumorspheroid platform will contribute to improve the dismal outcome of patients with HCC. Citation Format: Emilie Crouchet, Nuno Almeida, Sarah C. Durand, Marie Parnot, Marine A. Oudot, Fabio Giannone, Cloé Gadenne, Sara Cherradi, Natascha Roehlen, Antonio Saviano, Emanuele Emanuele Felli, Patrick Pessaux, Kazuaki Chayama, Hong Tuan F. Duong, Thomas F. Baumert, Catherine Schuster. A patient-derived hepatocellular carcinoma multicellular spheroid platform harnessing autologous patient serum to model the tumor microenvironment and treatment response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6765.

Metabolomics, Transcriptome and Single-Cell RNA Sequencing Analysis of the Metabolic Heterogeneity between Oral Cancer Stem Cells and Differentiated Cancer Cells.

Understanding the distinct metabolic characteristics of cancer stem cells (CSC) may allow us to better cope with the clinical challenges associated with them. In this study, OSCC cell lines (CAL27 and HSC3) and multicellular tumor spheroid (MCTS) models were used to generate CSC-like cells. Quasi-targeted metabolomics and RNA sequencing were used to explore altered metabolites and metabolism-related genes. Pathview was used to display the metabolites and transcriptome data in a KEGG pathway. The single-cell RNA sequencing data of six patients with oral cancer were analyzed to characterize in vivo CSC metabolism. The results showed that 19 metabolites (phosphoethanolamine, carbamoylphosphate, etc.) were upregulated and 109 metabolites (2-aminooctanoic acid, 7-ketocholesterol, etc.) were downregulated in both MCTS cells. Integration pathway analysis revealed altered activity in energy production (glycolysis, citric cycle, fatty acid oxidation), macromolecular synthesis (purine/pyrimidine metabolism, glycerophospholipids metabolism) and redox control (glutathione metabolism). Single-cell RNA sequencing analysis confirmed altered glycolysis, glutathione and glycerophospholipid metabolism in in vivo CSC. We concluded that CSCs are metabolically inactive compared with differentiated cancer cells. Thus, oral CSCs may resist current metabolic-related drugs. Our result may be helpful in developing better therapeutic strategies against CSC.

Multicellular tumor spheroid model to study the multifaceted role of tumor-associated macrophages in PDAC

Multicellular tumor spheroid model to study the multifaceted role of tumor-associated macrophages in PDAC

Antitumor activity of the investigational B7-H3 antibody-drug conjugate, vobramitamab duocarmazine, in preclinical models of neuroblastoma

IntroductionB7-H3 is a potential target for pediatric cancers, including neuroblastoma (NB). Vobramitamab duocarmazine (also referred to as MGC018 and herein referred to as vobra duo) is an investigational duocarmycin-based antibody-drug...

Mitochondria-targeted cyclometalated iridium-β-carboline complexes as potent non-small cell lung cancer therapeutic agents.

Natural products and metals play a crucial role in cancer research and the development of antitumor drugs. We designed and synthesized three new carboline-based cyclometalated iridium complexes [Ir(C-N)2(PPβC)](PF6), where PPβC=N-(1,10-phenanthrolin-5-yl)-1-phenyl-9H-pyrido[3,4-b]indole-3-carboxamide, C-N=2-phenylpyridine (ppy, Ir1), 2-(2,4-difluorophenyl) pyridine (dfppy, Ir2), 7,8-benzoquinoline (bzq, Ir3), by combining iridium with β-carboline derivative. These iridium complexes exhibited high potential antitumor effects after being promptly taken up by A549 cells. Accumulating in mitochondria rapidly and preferentially, Ir1-3 caused a series of changes in mitochondrial events, including the loss of mitochondrial membrane potential, the depletion of cellular ATP, and the elevation of reactive oxygen species, leading to significant death of A549 cells. Moreover, the activation of intracellular caspase pathway and apoptosis was further validated to contribute to iridium complexes-induced cytotoxicity. These novel iridium complexes exerted a prominent inhibitory effect on tumor growth in a three-dimensional multicellular tumor spheroid model.

Enriching Chemical Space of Bioactive Scaffolds by New Ring Systems: Benzazocines and Their Metal Complexes as Potential Anticancer Drugs.

The search for new scaffolds of medicinal significance combined with molecular shape enhances their innovative potential and continues to attract the attention of researchers. Herein, we report the synthesis, spectroscopic characterization (1H and 13C NMR, UV-vis, IR), ESI-mass spectrometry, and single-crystal X-ray diffraction analysis of a new ring system of medicinal significance, 5,6,7,9-tetrahydro-8H-indolo[3,2-e]benzazocin-8-one, and a series of derived potential ligands (HL1-HL5), as well as ruthenium(II), osmium(II), and copper(II) complexes (1a, 1b, and 2-5). The stability of compounds in 1% DMSO aqueous solutions has been confirmed by 1H NMR and UV-vis spectroscopy measurements. The antiproliferative activity of HL1-HL5 and 1a, 1b, and 2-5 was evaluated by in vitro cytotoxicity tests against four cancer cell lines (LS-174, HCT116, MDA-MB-361, and A549) and one non-cancer cell line (MRC-5). The lead compounds HL5 and its copper(II) complex 5 were 15× and 17×, respectively, more cytotoxic than cisplatin against human colon cancer cell line HCT116. Annexin V-FITC apoptosis assay showed dominant apoptosis inducing potential of both compounds after prolonged treatment (48 h) in HCT116 cells. HL5 and 5 were found to induce a concentration- and time-dependent arrest of cell cycle in colon cancer cell lines. Antiproliferative activity of 5 in 3D multicellular tumor spheroid model of cancer cells (HCT116, LS-174) superior to that of cisplatin was found. Moreover, HL5 and 5 showed notable inhibition potency against glycogen synthase kinases (GSK-3α and GSK-3β), tyrosine-protein kinase (Src), lymphocyte-specific protein-tyrosine kinase (Lck), and cyclin-dependent kinases (Cdk2 and Cdk5) (IC50 = 1.4-6.1 μM), suggesting their multitargeted mode of action as potential anticancer drugs.

Targeted alpha therapy with the 224Ra/212Pb-TCMC-TP-3 dual alpha solution in a multicellular tumor spheroid model of osteosarcoma.

Osteosarcoma patients with overt metastases at primary diagnosis have a 5-year survival rate of less than 20%. TP-3 is a murine IgG2b monoclonal antibody with high affinity for an epitope residing on the p80 osteosarcoma cell surface membrane antigen. The tumor-associated antigen p80 is overexpressed in osteosarcomas, and has very low normal tissue expression. We propose a novel dual alpha targeting solution containing two radionuclides from the same decay chain, including the bone-seeking 224Ra, and cancer cell-surface seeking 212Pb-TCMC-TP-3 for the treatment of osteoblastic bone cancers, circulating cancer cells and micrometastases. In this in vitro study, the cytotoxic effects of 212Pb-TCMC-TP-3 (single alpha solution) and 224Ra/212Pb-TCMC-TP-3 (dual alpha solution) were investigated in a multicellular spheroid model mimicking micrometastatic disease in osteosarcoma. OHS spheroids with diameters of 253 ± 98 μm treated with 4.5, 2.7, and 3.3 kBq/ml of 212Pb-TCMC-TP-3 for 1, 4, and 24 h, respectively, were disintegrated within 3 weeks. The 212Pb-TCMC-TP-3 induced a 7-fold delay in spheroid doubling time compared to a 28-times higher dose with the non-specific 212Pb-TCMC-rituximab. The 224Ra/212Pb-TCMC-TP-3 completely disintegrated spheroids with diameters of 218-476 μm within 3 and 2 weeks after 4 and 24 h incubation with 5 kBq/ml, respectively. Treatment with 1 kBq/ml of 224Ra/212Pb-TCMC-TP-3 for 24 h caused an 11.4-fold reduction in spheroid viability compared with unconjugated 224Ra/212Pb. The single and dual alpha solutions with TP-3 showed cytotoxicity in spheroids of clinically relevant size, which warrant further testing of the dual alpha solution using in vivo osteosarcoma models.

O-23 - Cytotoxicity of the bimodal [224Ra]RaCl2 and [212Pb]Pb-TCMC-TP-3 solution in a multicellular tumor spheroid model of osteosarcoma

O-23 - Cytotoxicity of the bimodal [224Ra]RaCl2 and [212Pb]Pb-TCMC-TP-3 solution in a multicellular tumor spheroid model of osteosarcoma

Bichromophoric BODIPY and Biotin Tagged Terpyridyl Ruthenium(II) Complexes for Cellular Imaging and Photodynamic Therapy

AbstractA perceived drawback of ruthenium(II) polypyridyl photosensitizers for phototherapeutic applications is their inadequate absorption in the visible region. Ru(II) dyads attached to light‐harvesting organic chromophores are studied to address this issue. Biotin‐appended compounds having one chromophore, namely BODIPY (boron‐dipyrromethene) (1) and Ru(II)‐(tpy)2 (2), or a dyad system containing BODIPY linked to Ru(II)‐(tpy)2 via a diphenylacetylene linker (3) were prepared and studied as photodetection agent and photosensitizes for Photodynamic Therapy (PDT) applications. The bichromophoric 3 with a strong absorption profile (ϵ≈71000 M−1 cm−1 at λmax=503 nm) and high singlet oxygen quantum yield (ΦΔ=0.63 in DMSO) was studied for PDT activity. This complex produced a superoxide anion radical via type‐I and singlet oxygen via type‐II photosensitization processes on light exposure, as evidenced from DNA photo‐cleavage experiments and in vitro DCFDA assay using reactive oxygen species scavengers/quenchers. Dyad 3 displayed an apoptotic photo‐cytotoxic effect against HeLa and H1299 cancer cells with a photocytotoxicity index (PI) value of >625 in HeLa cells with a PDT efficacy much superior to those of its monochromophoric analogs 1 and 2. The intrinsic emission of complex 3, utilized for cellular imaging, showed selectivity towards lysosomes. Finally, the remarkable potential of complex 3 was evidenced using a clinically relevant 3D multicellular tumor spheroid model.

Iridium (III) complexes induce cervical carcinoma apoptosis via disturbing cellular redox homeostasis disorder and inhibiting PI3K/AKT/mTOR pathway

Improvement of antineoplastic activity and selectivity is a main goal in the development of antineoplastic agents. Herein, we synthesized three new iridium (III) complexes: [Ir(ppy)2(FTTP)](PF6) (Ir1, ppy = 2-phenylpyridine, FTTP = 2-(3-fluoronaphthalen-2-yloxy)-1,4,8,9-tetraazatriphenylene), [Ir(bzq)2(FTTP)](PF6) (Ir2, bzq = benzo[h]quinolone), [Ir(piq)2(FTTP)](PF6) (Ir3, piq = 1-phenylisoquinoline). Ir1-3 exhibit excellent cytotoxicity against various cancer cells particularly towards human cervical carcinoma HeLa cells while remaining non-toxic to normal cell lines. Assays on 2D cell colony formation and 3D multicellular tumor spheroid model confirm that Ir1-3 can effectively inhibit the colony-forming and penetrate deeply into HeLa 3D multicellular tumor spheroid model exhibiting a notable cytotoxic effect, which was consistent with the results from the viability assays. Meanwhile, confocal microscopy shows a rapid uptake of Ir1-3 and co-localization experiments with subcellular markers reveal that Ir1-3 locate mainly at the mitochondria. Further investigation of the mechanism indicated the complexes Ir1-3 promote the excessive generation of ROS, inhibit glutathione and thioredoxin reductase that effectively interferes with the intracellular redox balance, induce oxidative stress and result in caspase-dependent apoptosis. Moreover, the ROS-mediated inactivation of the PI3K (phosphatidylinositol 3-kinase)/AKT (protein kinase B)/mTOR (mammalian target of rapamycin) pathway, DNA damage combing with suppression of the cyclin D1/CDK4/6 activity arrested cell cycle in the G0/G1 phase are involved in complexes-induced cell apoptosis. Finally, assays on xenografted cervical carcinoma mouse model confirm the excellent biocompatibility and antineoplastic efficiency of Ir3 in vivo. Collectively, this work offers building blocks for developing iridium (III) complexes as clinical application potential.

The impact of temozolomide and lonafarnib on the stemness marker expression of glioblastoma cells in multicellular spheroids

Glioblastoma multiforme (GBM) is a highly malignant brain tumor with a poor prognosis. The GBM microenvironment is highly heterogeneous and is composed of many cell types including astrocytes and endothelial cells (ECs) along with tumor cells, which are responsible for heightened resistance to standard chemotherapeutic drugs such as Temozolomide (TMZ). Here, we investigated how drug treatments impact stemness marker expression of GBM cells in multicellular tumor spheroid (MCTS) models. Co- and tri-culture MCTS constructed using U87-MG GBM cells, astrocytes, and/or ECs were cultured for 7 days. At Day 7, 5μM lonafarnib (LNF), 100 μM TMZ, or combination of 5μM LNF + 100 μM TMZ was added and the MCTS were cultured for an additional 48 h. We assessed the spheroid sizes and expression of stemness markers- NESTIN, SOX2, CD133, NANOG, and OCT4- through qRT-PCR and immunostaining. Following 48 h treatment with LNF, TMZ or their combination (LNF + TMZ), the spheroid sizes decreased compared to the untreated control. We also observed that the expression of most of the stemness markers significantly increased in the LNF + TMZ treated condition as compared to the untreated condition. These results indicate that drug treatment can influence the stemness marker expression of GBM cells in MCTS models and these aspects must be considered while evaluating therapies. In future, by incorporating other relevant cell types, we can further our understanding of their crosstalk, eventually leading to the development of new therapeutic strategies.

In vitro 2D and 3D cancer models to evaluate compounds that modulate macrophage polarization

In vitro cancer models that can identify novel immunomodulating compounds are essential. Using a 3D multicellular tumor spheroid (MCTS) model comprising cancer cells, fibroblasts, and macrophages, we tested tumor-associated macrophage (TAM)-inhibiting compounds (CCL2 Ab, CSF1R inhibitor, CSF1R Ab) and TAM-reprograming compounds (poly I:C, CD40 Ab, CD40 ligand) for their effects on monocyte infiltration and polarization in tumor spheroids. For characterization of macrophage polarization, we measured the expression of CD206, CD163, CD86, MHC II, CD40, and CD14 and measured 43 soluble factors in the 3D MCTS cultures. 2D macrophage models were evaluated for comparison. A CSF1R inhibitor prevented infiltration of monocytes into pancreatic cancer spheroids, and macrophages treated with the inhibitor showed decreased expression of M2 markers. Treatment with a CD40 ligand and poly I:C induced M1 macrophage polarization in our models. We propose that these models can be used to improve the drug screening process of anti-cancer immunotherapies targeting macrophages.

Non-Destructive Evaluation of Regional Cell Density Within Tumor Aggregates Following Drug Treatment.

Multicellular tumor spheroid (MCTSs) models have demonstrated increasing utility for in vitro study of cancer progression and drug discovery. These relatively simple avascular constructs mimic key aspects of in vivo tumors, such as 3D structure and pathophysiological gradients. MCTSs models can provide insights into cancer cell behavior during spheroid development and in response to drugs; however, their requisite size drastically limits the tools used for non-destructive assessment. Optical Coherence Tomography structural imaging and Imaris 3D analysis software are explored for rapid, non-destructive, and label-free measurement of regional cell density within MCTSs. This approach is utilized to assess MCTSs over a 4-day maturation period and throughout an extended 5-day treatment with Trastuzumab, a clinically relevant anti-HER2 drug. Briefly, AU565 HER2+ breast cancer MCTSs were created via liquid overlay with or without the addition of Matrigel (a basement membrane matrix) to explore aggregates of different morphologies (thicker, disk-like 2.5D aggregates or flat 2D aggregates, respectively). Cell density within the outer region, transitional region, and inner core was characterized in matured MCTSs, revealing a cell-density gradient with higher cell densities in core regions compared to outer layers. The matrix addition redistributed cell density and enhanced this gradient, decreasing outer zone density and increasing cell compaction in the cores. Cell density was quantified following drug treatment (0 h, 24 h, 5 days) within progressively deeper 100 µm zones to assess potential regional differences in drug response. By the final timepoint, nearly all cell death appeared to be constrained to the outer 200 µm of each aggregate, while cells deeper in the aggregate appeared largely unaffected, illustrating regional differences in the drug response, possibly due to limitations in drug penetration. The current protocol provides a unique technique to non-destructively quantify regional cell density within dense cellular tissues and measure it longitudinally.

Multicellular Tumor Spheroids in Nanomedicine Research: A Perspective.

Multicellular tumor spheroids are largely exploited in cancer research since they are more predictive than bi-dimensional cell cultures. Nanomedicine would benefit from the integration of this three-dimensional in vitro model in screening protocols. In this brief work, we discuss some of the issues that cancer nanomedicine will need to consider in the switch from bi-dimensional to three-dimensional multicellular tumor spheroid models.

Anti-Cancer Effects of YAP Inhibitor (CA3) in Combination with Sorafenib against Hepatocellular Carcinoma (HCC) in Patient-Derived Multicellular Tumor Spheroid Models (MCTS).

Simple SummaryActivation of YAP/TAZ (mediators of Hippo signaling) is associated with the development of liver cancer. The expression level of YAP is known to relate to chemoresistance. However, the therapeutic effect of YAP/TAZ inhibition when combined with sorafenib and conventional chemotherapy in HCC is not known. Recent studies have highlighted the importance of the tumor microenvironment (TME) in chemoresistance. The multicellular tumor spheroid (MCTS) model has emerged as a promising tool for studying cancer drugs as it mimics actual TME. Here, we aimed at assessing the YAP/TAZ expression level of HCCs and identifying the therapeutic effects of CA3 (novel YAP inhibitor) when combined with sorafenib using a patient-derived MCTS model. We established patient-derived MCTS and confirmed that patient-derived MCTS with high YAP/TAZ expression responded more sensitively to the combination therapy (sorafenib with CA3) than MCTS with low or medium YAP/TAZ expression. These findings suggest that the YAP/TAZ inhibitor may serve as a potential therapeutic strategy to enhance sensitivity to sorafenib in HCCs with high YAP/TAZ expression.Purpose: To assess the expression levels of YAP and TAZ in patient-derived HCC tissue and identify the effects of YAP/TAZ inhibition depending on the baseline YAP/TAZ expression when combined with sorafenib using a patient-derived multicellular tumor spheroid (MCTS) model. Methods: Primary HCC cell lines were established from patient-derived tissue. Six patient-derived HCC cell lines were selected according to YAP/TAZ expression on Western blot: high, medium, low. Then, MCTS was generated by mixing patient-derived HCC cells and stroma cells (LX2, WI38, and HUVECs) and YAP/TAZ expression was assessed using Western blot. Cell viability of MCTS upon 48 h of drug treatment (sorafenib, sorafenib with CA3 0.1 µM, and CA3 (novel YAP1 inhibitor)) was analyzed. Results: Out of six patient-derived HCC cell lines, cell lines with high YAP/TAZ expression at the MCTS level responded more sensitively to the combination therapy (Sorafenib + CA3 0.1 μM) despite the potent cytotoxic effect of CA3 exhibited in all of the patient-derived HCCs. Conclusion: Targeting YAP/TAZ inhibition using the novel YAP1 inhibitor CA3 could be a promising therapeutic strategy to enhance sensitivity to sorafenib especially in HCCs with high YAP/TAZ expression in MCTS.

Bisdemethoxycurcumin sensitizes the response of cisplatin resistant non-small cell lung carcinoma cell lines by activating apoptosis and autophagy

Lung cancer belongs to the most frequent and deadliest cancer types worldwide, non-small cell lung carcinoma (NSCLC) being the most frequent type. Development of chemoresistance in NSCLC patients is common and responsible for bad outcome. Curcuminoids are naturally occurring substances with prominent cytotoxic effects in different cancer cells. Here we analyzed influence of bisdemethoxycurcumin (BDMC) on phenotype and molecular mechanisms in cisplatin-sensitive NSCLC cell lines (A549 and H460) and their cisplatin-resistant counterparts. NSCLC cell lines were exposed to BDMC and analyzed by cell viability, proliferation, and motility assays, as well as fluorescence-activated cell sorting. Immunoblotting was assessed to detect apoptosis and autophagy. Colony-formation assay and multicellular tumor spheroid model were used to investigate the effects of BDMC. Expression levels of different Hedgehog-pathway genes were determined by RT-qPCR analysis. We identified substantial cytotoxic effects of BDMC on NSCLC cells in general and on cisplatin-resistant NSCLC cells in special. BDMC markedly decreased the cell viability by inducing apoptosis and autophagy in a cell-type specific manner. BDMC emphasized cisplatin-induced cell death and inhibited cell cycle progression of cisplatin-resistant NSCLC cells. Scratch-closure, colony formation, and multicellular spheroid growth in cisplatin-resistant NSCLC cell lines were inhibited by BDMC. Expression profile analyses of different Hedgehog-pathway regulatory genes showed that Gli1, the mean transcriptional regulator of this pathway, was markedly decreased upon the BDMC treatment, this decrement being most prominent in cisplatin-resistant cells. Our data identified BDMC as a potent substance that may be suitable for combined cisplatin-based therapy in cisplatin-resistant subpopulation of NSCLC patients.

Before in vivo studies: In vitro screening of sphingomyelin nanosystems using a relevant 3D multicellular pancreatic tumor spheroid model

Sphingomyelin nanosystems have already shown to be promising carriers for efficient delivery of anticancer drugs. For further application in the treatment of pancreatic tumor, the investigation on relevant in vitro models able to reproduce its physio-pathological complexity is mandatory. Accordingly, a 3D heterotype spheroid model of pancreatic tumor has been herein constructed to investigate the potential of bare and polyethylene glycol-modified lipid nanosystems in terms of their ability to penetrate the tumor mass and deliver drugs. Regardless of their surface properties, the lipid nanosystems successfully diffused through the spheroid without inducing toxicity, showing a clear safety profile. Loading of the bare nanosystems with a lipid prodrug of gemcitabine was used to evaluate their therapeutic potential. While the nanosystems were more effective than the free drug on 2D cell monocultures, this advantage, despite their efficient penetration capacity, was lost in the 3D tumor model. The latter, being able to mimic the tumor and its microenvironment, was capable to provide a more realistic information on the cell sensitivity to treatments. These results highlight the importance of using appropriate 3D tumor models as tools for proper in vitro evaluation of nanomedicine efficacy and their timely optimisation, so as to identify the best candidates for later in vivo evaluation.

Pediatric multicellular tumor spheroid models illustrate a therapeutic potential by combining BH3 mimetics with Natural Killer (NK) cell-based immunotherapy

The induction of apoptosis is a direct way to eliminate tumor cells and improve cancer therapy. Apoptosis is tightly controlled by the balance of pro- and antiapoptotic Bcl-2 proteins. BH3 mimetics neutralize the antiapoptotic function of Bcl-2 proteins and are highly promising compounds inducing apoptosis in several cancer entities including pediatric malignancies. However, the clinical application of BH3 mimetics in solid tumors is impeded by the frequent resistance to single BH3 mimetics and the anticipated toxicity of high concentrations or combination treatments. One potential avenue to increase the potency of BH3 mimetics is the development of immune cell-based therapies to counteract the intrinsic apoptosis resistance of tumor cells and sensitize them to immune attack. Here, we describe spheroid cultures of pediatric cancer cells that can serve as models for drug testing. In these 3D models, we were able to demonstrate that activated allogeneic Natural Killer (NK) cells migrated into tumor spheroids and displayed cytotoxicity against a wide range of pediatric cancer spheroids, highlighting their potential as anti-tumor effector cells. Next, we investigated whether treatment of tumor spheroids with subtoxic concentrations of BH3 mimetics can increase the cytotoxicity of NK cells. Notably, the cytotoxic effects of NK cells were enhanced by the addition of BH3 mimetics. Treatment with either the Bcl-XL inhibitor A1331852 or the Mcl-1 inhibitor S63845 increased the cytotoxicity of NK cells and reduced spheroid size, while the Bcl-2 inhibitor ABT-199 had no effect on NK cell-mediated killing. Taken together, this is the first study to describe the combination of BH3 mimetics targeting Bcl-XL or Mcl-1 with NK cell-based immunotherapy, highlighting the potential of BH3 mimetics in immunotherapy.