Impact of multicellular tumor spheroids as an in vivo‑like tumor model on anticancer drug response

Apoptotic effect of 5-fluorouracil-doxorubicin combination on colorectal cancer cell monolayers and spheroids

BACKGROUND

Drug combination studies help to improve new treatment approaches for colon cancer. Tumor spheroids (3D) are better models than traditional 2-dimensional cultures (2D) to evaluate cellular responses to chemotherapy drugs. The cultivation of cancer cells in 2D and 3D cultures affects the apoptotic process, which is a major factor influencing the response of cancer cells to chemotherapeutic drugs. In this study, the antiproliferative effects of 5-fluorouracil (5-FU) and doxorubicin (DOX) were investigated separately and in combination using 2D and 3D cell culture models on two different colon cancer cell lines, HT-29 (apoptosis-resistant cells) and Caco-2 2 (apoptosis-susceptible cells).

METHODS

The effect of the drugs on the proliferation of both colon cancer cells was determined by performing an MTT assay in 2D culture. The apoptotic effect of 5-FU and DOX, both as single agents and in combination, was assessed in 2D and 3D cultures through quantitative real-time polymerase chain reaction analysis. The expression of apoptotic genes, such as caspases, p53, Bax, and Bcl-2, was quantified.

RESULTS

It was found that the mRNA expression of proapoptotic genes was significantly upregulated, whereas the mRNA expression of the antiapoptotic Bcl-2 gene was significantly downregulated in both colon cancer models treated with 5-FU, DOX, and 5-FU + DOX.

CONCLUSION

The results indicated that the 5-FU + DOX combination therapy induces apoptosis and renders 5-FU and DOX more effective at lower concentrations compared to their alone use. This study reveals promising results in reducing the potential side effects of treatment by enabling the use of lower drug doses.

The effects of microgravity on stem cells and the new insights it brings to tissue engineering and regenerative medicine

Conventional two-dimensional (2D) cell culture techniques may undergo modifications in the future, as life scientists have widely acknowledged the ability of three-dimensional (3D) in vitro culture systems to accurately simulate in vivo biology. In recent years, researchers have discovered that microgravity devices can address many challenges associated with 3D cell culture. Stem cells, being pluripotent cells, are regarded as a promising resource for regenerative medicine. Recent studies have demonstrated that 3D culture in microgravity devices can effectively guide stem cells towards differentiation and facilitate the formation of functional tissue, thereby exhibiting advantages within the field of tissue engineering and regenerative medicine. Furthermore, We delineate the impact of microgravity on the biological behavior of various types of stem cells, while elucidating the underlying mechanisms governing these alterations. These findings offer exciting prospects for diverse applications.

Label-free visualization and quantification of the drug-type-dependent response of tumor spheroids by dynamic optical coherence tomography

We demonstrate label-free dynamic optical coherence tomography (D-OCT)-based visualization and quantitative assessment of patterns of tumor spheroid response to three anti-cancer drugs. The study involved treating human breast adenocarcinoma (MCF-7 cell-line) with paclitaxel (PTX), tamoxifen citrate (TAM), and doxorubicin (DOX) at concentrations of 0 (control), 0.1, 1, and 10 µM for 1, 3, and 6 days. In addition, fluorescence microscopy imaging was performed for reference. The D-OCT imaging was performed using a custom-built OCT device. Two algorithms, namely logarithmic intensity variance (LIV) and late OCT correlation decay speed (OCDS[Formula: see text]) were used to visualize the tissue dynamics. The spheroids treated with 0.1 and 1 µM TAM appeared similar to the control spheroid, whereas those treated with 10 µM TAM had significant structural corruption and decreasing LIV and OCDS[Formula: see text] over treatment time. The spheroids treated with PTX had decreasing volumes and decrease of LIV and OCDS[Formula: see text] signals over time at most PTX concentrations. The spheroids treated with DOX had decreasing and increasing volumes over time at DOX concentrations of 1 and 10 µM, respectively. Meanwhile, the LIV and OCDS[Formula: see text] signals decreased over treatment time at all DOX concentrations. The D-OCT, particularly OCDS[Formula: see text], patterns were consistent with the fluorescence microscopic patterns. The diversity in the structural and D-OCT results among the drug types and among the concentrations are explained by the mechanisms of the drugs. The presented results suggest that D-OCT is useful for evaluating the difference in the tumor spheroid response to different drugs and it can be a useful tool for anti-cancer drug testing.

Targeting BRD4 and PI3K signaling pathways for the treatment of medulloblastoma

Medulloblastoma (MB) is a malignant pediatric brain tumor which shows upregulation of MYC and sonic hedgehog (SHH) signaling. SHH inhibitors face acquired resistance, which is a major cause of relapse. Further, direct MYC oncogene inhibition is challenging, inhibition of MYC upstream insulin-like growth factor/ phosphatidylinositol-4,5-bisphosphate 3-kinase (IGF/PI3K) is a promising alternative. While PI3K inhibition activates resistance mechanisms, simultaneous inhibition of bromodomain-containing protein 4 (BRD4) and PI3K can overcome resistance. We synthesized a new molecule 8-(2,3-dihydrobenzo[b] [1, 4] dioxin-6-yl)-2-morpholino-4H-chromen-4-one (MDP5) that targets both BRD4 and PI3K pathways. We used X-ray crystal structures and a molecular modeling approach to confirm the interactions between MDP5 with bromo domains (BDs) from both BRD2 and BRD4, and molecular modeling for PI3K binding. MDP5 was shown to inhibit target pathways and MB cell growth in vitro and in vivo. MDP5 showed higher potency in DAOY cells (IC50 5.5 μM) compared to SF2523 (IC50 12.6 μM), and its IC50 values in HD-MB03 cells were like SF2523. Treatment of MB cells with MDP5 significantly decreased colony formation, increased apoptosis, and halted cell cycle progression. Further, MDP5 was well tolerated in NSG mice bearing either xenograft or orthotopic MB tumors at the dose of 20 mg/kg, and significantly reduced tumor growth and prolonged animal survival.

Anthracene dimer cross-linked, washing- and sterilization-free hydrogel films for multicellular spheroid generation

Three-dimensional multicellular spheroids are better in vitro cell models than two-dimensional cell monolayers; however, their applications are limited by their difficult production. PHEMA hydrogel films with honeycomb-like wrinkled patterns have been developed for high-throughput generation of multicellular spheroids with a uniform shape and size; however, the films are prepared by polymerization of the HEMA monomer, and should be washed extensively before use. Here to synthesize washing-free PHEMA hydrogel films, linear anthracene-functionalized PHEMA polymers were first synthesized by the free-radical copolymerization of HEMA and an anthracene-containing vinyl monomer. Smooth films were then prepared from the linear polymers in the wells of cell culture plates by solution casting. They were cross-linked via photo-dimerization of anthracene groups by exposing to 365 nm UV light, and patterned spontaneously by adding water to swell them. The swelling degree of the films and hence the shape of the wrinkled patterns could be facilely adjusted by adjusting the anthracene content in the linear polymers. If necessary, the cross-link density of the film and thus the shape of the wrinkled patterns could be callbacked by irradiating with 254 nm UV light, thanks to the reversibility of the photo-dimerization of anthracene. The as-prepared films exhibit a high biocompatibility and support cell growth well even without washing and sterilization. The high biocompatibility is attributed to the facts that no low molecular weight monomer, crosslinker and initiator were involved in the film preparation, and the photo-dimerization of anthracene groups produces no by-products. The films are sterilized simultaneously when cross-linked with UV irradiation, thus avoiding an additional sterilization step. PHEMA films with long-range ordered hexagonal wrinkled patterns were selected to generate multicellular spheroids of tumor cell lines. The resulting spheroids exhibit a narrow size distribution and high cell viability. Preliminary tests demonstrated their potential in the screening of anti-cancer drugs.

Characteristics and Resistance to Cisplatin of Human Neuroblastoma Cells Co-Cultivated with Immune and Stromal Cells

We investigated the features of the morphology and cytokine profiles of neuroblastoma SH-SY5Y cells, bone marrow-derived mesenchymal stromal/stem cells (BM-MSCs), and peripheral blood mononuclear cells (PBMCs) in double (BM-MSCs + SH-SY5Y cells) and triple (BM-MSCs + SH-SY5Y cells + PBMCs) co-cultures incubated on plastic and Matrigel. Cells in the co-cultures communicated by vesicular transport and by exchanging membrane and cytoplasmic components. The cytokine profile of double and triple co-cultures incubated on Matrigel and plastic had differences and showed the highest concentration of a number of chemokines/cytokines, such as CXCL8/IL-8, I-TAC/CXCL11, IP10/CXCL10, MDC/CCL22, MIP-1α/CCL3, IL-1β, ENA-78/CXCL5, Gro-α/CXCL1, MCP-1/CCL2, TERC/CCL25, CXCL8/IL-8, and IL-6. High concentrations of inflammatory chemokines/cytokines in the conditioned medium of triple co-culture form a chronic inflammation, which brings the presented co-cultivation system closer to a natural tumor. Triple co-cultures were more resistant to cisplatin (CDDP) than the double- and monoculture of SH-SY5Y. The mRNA levels of BCL2, BCL2L1, RAC1, CAV1, CASP3, and BAX genes were changed in cells after co-culturing and CDDP treatment in double and triple co-cultures. The expression of the BCL2, BAX, CAV1, and CASP3 proteins in SH-SY5Y cells after the triple co-culture and CAV1 and BAX protein expression in SH-SY5Y cells after the double co-culture were determined. This study demonstrated the nature of the cellular interactions between components of tumor niche and the intercellular influence on chemoresistance observed in our tumor model, which should enable the development of novel test systems for anti-tumor agents.

A rapid high throughput bioprinted colorectal cancer spheroid platform forin vitrodrug- and radiation-response

We describe the development of a high-throughput bioprinted colorectal cancer (CRC) spheroid platform with high levels of automation, information content, and low cell number requirement. This is achieved via the formulation of a hydrogel bioink with a compressive Young's modulus that is commensurate with that of colonic tissue (1-3 kPa), which supports exponential growth of spheroids from a wide range of CRC cell lines. The resulting spheroids display tight cell-cell junctions, bioink matrix-cell interactions and necrotic hypoxic cores. By combining high content light microscopy imaging and processing with rapid multiwell plate bioprinting, dose-response profiles are generated from CRC spheroids challenged with oxaliplatin (OX) and fluorouracil (5FU), as well as radiotherapy. Bioprinted CRC spheroids are shown to exhibit high levels of chemoresistance relative to cell monolayers, and OX was found to be significantly less effective against tumour spheroids than in monolayer culture, when compared to 5FU.

Semaphorin 3F induces colorectal cancer cell chemosensitivity by promoting P27 nuclear export

Colorectal adenocarcinoma (CRC) is the third most common malignancy worldwide. Metastatic CRC has a poor prognosis because of chemotherapy resistance. Our previous study demonstrated that semaphorin 3F (SEMA3F) signaling may contribute to reversing chemotherapy resistance in CRC cells by reducing E-cadherin and integrin αvβ3 expression levels. Another study showed that upregulation of p27 significantly increase the expression of E-cadherin and integrin. This study aimed to evaluate the effect of SEMA3F on P27 and whether it can reverse resistance in CRC cells. We compared the chemosensitivity of human colorectal cancer cell lines with different SEMA3F expression levels to 5-Fu through cell experiment and animal experiment. Then the interaction between SEMA3F and p27 and its possible mechanism were explored by Western Blot, immunofluorescence and immunocoprecipitation. We also compared the disease-free survival of 118 CRC patients with high or low expression of SEMA3F.The results showed that overexpresstion of SEMA3F enhanced the chemotherapy sensitivity and apoptosis of CRC cells in vitro and in vivo. Among 118 postoperative CRC specimens, the disease-free survival of patients with positive SEMA3F expression was significantly longer than that with negative SEMA3F expression after adjuvant treatment. Upregulation of SEMA3F in multicellular spheroid culture (MSC) could increase p27 phosphorylation at serine 10 (Ser10), subsequently promote the cytosolic translocation of P27. Overall, our results reveal a novel molecular mechanism: SEMA3F mediates the degradation of p27 and regulates its subcellular localization to enhance chemosensitivity to 5-Fu in CRC cells, rather than inhibits p27 expression.

5-fluorouracil treatment of patient-derived scaffolds from colorectal cancer reveal clinically critical information

BACKGROUND

Colorectal cancer is a commonly diagnosed cancer worldwide. Unfortunately, many patients do not respond to standard chemotherapy treatments and develop disease relapse and metastases. Besides cancer cell specific genetic changes, heterogeneity in the tumor microenvironment contribute to the clinical presentation of the disease and can potentially also influence drug resistance. By using a recently developed patient-derived scaffold method monitoring how a standardized reporter cancer cell line adapts to various microenvironments treated with chemotherapy, we wanted to clarify how individual patient specific microenvironments influence the chemotherapy response in colorectal cancer.

METHODS

Surgically resected colorectal cancer specimens from 89 patients were decellularized to produce patient-derived scaffold, which were seeded with HT29 cells, cultured for 3 weeks, and treated with 5-fluorouracil. Gene expression changes of adapted and treated HT29 cells were monitored by qPCR and compared with clinical parameters including disease-free survival.

RESULTS

The effects of 5-fluorouracil treatment varied between different patient-derived scaffold, but generally induced a reduced expression of proliferation genes and increased expression of pluripotency and epithelial-to-mesenchymal transition genes. Interestingly, patient-derived scaffold cultures obtained from patients with disease recurrences showed a significantly less pronounced anti-proliferative effect of 5-fluorouracil and more pronounced increase of pluripotency, with MKI67 and POU5F1 being among the most significant genes linked to disease relapse in colorectal cancer.

CONCLUSIONS

Colorectal patient-derived scaffold can decode clinically relevant tumor microenvironmental influence of 5-fluorouracil treatment effects opening up for optimized precision medicine in colorectal cancer treatment.

Three-dimensional dynamics optical coherence tomography for tumor spheroid evaluation

We present a completely label-free three-dimensional (3D) optical coherence tomography (OCT)-based tissue dynamics imaging method for visualization and quantification of the metabolic and necrotic activities of tumor spheroid. Our method is based on a custom 3D scanning protocol that is designed to capture volumetric tissue dynamics tomography images only in a few tens of seconds. The method was applied to the evaluation of a tumor spheroid. The time-course viability alteration and anti-cancer drug response of the spheroid were visualized qualitatively and analyzed quantitatively. The similarity between the OCT-based dynamics images and fluorescence microscope images was also demonstrated.

The Influence of Antitumor Unsymmetrical Bisacridines on 3D Cancer Spheroids Growth and Viability

The culture of 3D spheroids is a promising tool in drug development and testing. Recently, we synthesized a new group of compounds, unsymmetrical bisacridines (UAs), which exhibit high cytotoxicity against various human cell lines and antitumor potency against several xenografts. Here, we describe the ability of four UAs—C-2028, C-2041, C-2045, and C-2053—to influence the growth of HCT116 and H460 spheres and the viability of HCT116 cells in 3D culture compared with that in 2D standard monolayer culture. Spheroids were generated using ultra-low-attachment plates. The morphology and diameters of the obtained spheroids and those treated with UAs were observed and measured under the microscope. The viability of cells exposed to UAs at different concentrations and for different incubation times in 2D and 3D cultures was assessed using 7-AAD staining. All UAs managed to significantly inhibit the growth of HCT116 and H460 spheroids. C-2045 and C-2053 caused the death of the largest population of HCT116 spheroid cells. Although C-2041 seemed to be the most effective in the 2D monolayer experiments, in 3D conditions, it turned out to be the weakest compound. The 3D spheroid culture seems to be a suitable method to examine the efficiency of new antitumor compounds, such as unsymmetrical bisacridines.

Sporadic cell death in macroscale 3D tumor grafts with high drug resistance by activating cell-ECM interactions

In the tumor microenvironment (TME), the extracellular matrix (ECM) provides a dynamic structure for cell adhesion and cancer cell motility, such as migration and invasion, as well as remodeling. Matrix metalloproteinases (MMPs) promote cancer cell motility, which contributes to inducing drug resistance and thereby acquiring aggressive features. The drug resistance-induced 3Din vitrotumor model can be an effective model for therapeutic strategies for anticancer drugs targeting aggressive cancer cells. Here, we describe highly drug-resistant multicellular tumoroids (MCTs)-ECM tumor grafts under a macroscale dense 3Din vitromodel through a combination of numerous MCTs and a collagen matrix. MCTs-ECM tumor grafts promote the high activity of MMP2 and MMP9 compared to general MCTs and induced cancer cell motility. Then, after the administration of anticancer drugs, the tumor grafts show increased drug resistance, with both the sporadic distribution of necrotic cells and the reduction of apoptotic portions, by activating cancer cell motility. MCTs-ECM tumor graft could be useful as a macroscale tumor graft model for inducing drug resistance by activating cancer cell motility and evaluating the efficacy of anticancer drugs targeting cancer with aggressive features.

PE38-based gene therapy of HER2-positive breast cancer stem cells via VHH-redirected polyamidoamine dendrimers

Breast cancer stem cells (BCSCs) resist conventional treatments and cause tumor recurrence. Almost 25% of breast cancers overexpress human epidermal growth factor receptor-2 (HER2). Here we developed a novel multi-targeted nanosystem to specifically eradicate HER2⁺ BCSCs. Plasmids containing CXCR1 promoter, PE38 toxin, and 5′UTR of the basic fibroblast growth factor-2 (bFGF 5'UTR) were constructed. Polyamidoamine (PAMAM) dendrimers functionalized with anti-HER2 VHHs were used for plasmid delivery. Stem cell proportion of MDA-MB-231, MDA-MB-231/HER2⁺ and MCF-10A were evaluated by mammosphere formation assay. Hanging drop technique was used to produce spheroids. The uptake, gene expression, and killing efficacy of the multi-targeted nanosystem were evaluated in both monolayer and spheroid culture. MDA-MB-231/HER2⁺ had higher ability to form mammosphere compared to MCF-10A. Our multi-targeted nanosystem efficiently inhibited the mammosphere formation of MDA-MB-231 and MDA-MB-231/HER2⁺ cells, while it was unable to prevent the mammosphere formation of MCF-10A. In the hanging drop culture, MDA-MB-231/HER⁺ generated compact well-rounded spheroids, while MCF-10A failed to form compact cellular masses. The multi-targeted nanosystem showed much better uptake, higher PE38 expression, and subsequent cell death in MDA-MB-231/HER2⁺ compared to MCF-10A. However, the efficacy of our targeted toxin gene therapy was lower in MDA-MB-231/HER2⁺ spheroids compared with that in the monolayer culture. the combination of the cell surface, transcriptional, and translational targeting increased the stringency of the treatment.

Potent PBS/Polysorbate-Soluble Transplatin-Derived Porphyrin-Based Photosensitizers for Photodynamic Therapy

In this study, we addressed an important drawback of our previously reported tetraplatinated (metallo)porphyrin-based photosensitizers (PSs) for photodynamic therapy (PDT), namely, the poor solubility in aqueous media. We aimed to create tetraplatinated porphyrin-based PSs that are soluble in aqueous media modified with polysorbate (Tween) and do not need to be pre-dissolved in organic solvents. A structural optimization of the previously reported PSs resulted in the synthesis of an extremely potent novel porphyrin-based PS. The novel PS displays effective phototoxicity upon light irradiation against multicellular tumor spheroids and has a phototoxic index (PI) of 6030 in HeLa cells. This PI value is, to the best of our knowledge, the highest value reported for any porphyrin so far.

Anticancer Activity of Ipomoea purpurea Leaves Extracts in Monolayer and Three-Dimensional Cell Culture

Cancer is a leading cause of death and a vital health care challenge in the world. Hence, this work was conducted to determine the in vitro anticancer property and also the molecular mechanism of aqueous and organic extracts of Ipomoea purpurea leaves in three human cancer cell lines, including A-549 (human lung cancer), HepG-2 (human liver cancer), MDA-MB-231 (human breast cancer), and MCF-10A (breast normal cell line). In vitro cytotoxic potential of organic extracts, such as hexane, chloroform, ethyl-acetate, methanol, and aqueous extract was examined using a standard (3-(4,5-dimethylthiazole)-2,5-diphenyltetrazolium bromide) MTT method in both monolayer two-dimensional (2D) and spheroids multicellular three-dimensional (3D) cultures. The MTT assay data showed that methanol and chloroform extracts of I. purpurea leaves had the antiproliferative effect on lung and breast cancer cells with IC₅₀ of 53.62 ± 0.07 and 124.5 ± 0.01 µg/mL, respectively. The results of further examinations, such as dual acridine orange/ethidium bromide, Annexin V-FITC/PI, and caspase-3 colorimetric assay, confirmed that methanol and chloroform extracts of I. purpurea as the most potent cytotoxic extracts might contain a variety of phytochemicals, promoting apoptosis in lung and breast cancer cells. The present research findings suggested that methanolic extract of I. purpurea leaves induced S-phase cell cycle arrest and intrinsic pathway of apoptosis in A-549 lung cancer cells. The study further showed that I. purpurea could be a helpful candidate for cancer treatment.

Afatinib-loaded inhalable PLGA nanoparticles for localized therapy of non-small cell lung cancer (NSCLC)-development and in-vitro efficacy

Afatinib (AFA) is a potent aniline-quinazoline derivative, approved by the Food and Drug Administration (FDA) in 2013, as a first-line treatment for metastatic non-small cell lung cancer (NSCLC). However, its clinical application is highly limited by its poor solubility, and consequently low bioavailability. We hypothesize that loading of AFA into biodegradable PLGA nanoparticles for localized inhalational drug delivery will be instrumental in improving therapeutic outcomes in NSCLC patients. Formulated AFA nanoparticles (AFA-NP) were evaluated for physicochemical properties (particle size: 180.2 ± 15.6 nm, zeta potential: - 23.1 ± 0.2 mV, % entrapment efficiency: 34.4 ± 2.3%), formulation stability, in-vitro aerosol deposition behavior, and anticancer efficacy. Stability studies revealed the physicochemical stability of AFA-NP. Moreover, AFA-NP exhibited excellent inhalable properties (mass median aerodynamic diameter (MMAD): 4.7 ± 0.1 μm; fine particle fraction (FPF): 77.8 ± 4.3%), indicating efficient particle deposition in deep lung regions. With respect to in-vitro drug release, AFA-NP showed sustained drug release with cumulative release of 56.8 ± 6.4% after 48 h. Cytotoxic studies revealed that encapsulation of AFA into PLGA nanoparticles significantly enhanced its cytotoxic potential in KRAS-mutated NSCLC cell lines (A549, H460). Cellular uptake studies revealed enhanced internalization of coumarin-loaded nanoparticles compared to plain coumarin in A549. In addition, 3D tumor spheroid studies demonstrated superior efficacy of AFA-NP in tumor penetration and growth inhibition. To conclude, we have established in-vitro efficacy of afatinib-loaded PLGA nanoparticles as inhalable NSCLC therapy, which will be of great significance when designing preclinical and clinical studies. Graphical abstract.

Elucidating a Thermoresponsive Multimodal Photo-Chemotherapeutic Nanodelivery Vehicle to Overcome the Barriers of Doxorubicin Therapy

In an attempt to circumvent the major pitfalls associated with conventional chemotherapy including drug resistance and off-target toxicity, we have adopted a strategy to simultaneously target both mitochondrial DNA (Mt-DNA) and nuclear DNA (n-DNA) with the aid of a targeted theranostic nanodelivery vehicle (TTNDV). Herein, folic acid-anchored p-sulfo-calix[4]arene (SC₄)-capped hollow gold nanoparticles (HGNPs) were meticulously loaded with antineoplastic doxorubicin (Dox) and its mitochondrion-targeted analogue, Mt-Dox, in a pretuned ratio (1:100) for sustained thermoresponsive release of cargo. This therapeutic strategy was enabled to eradicate both n-DNA and Mt-DNA leaving no space to develop drug resistance. The SC₄-capped HGNPs (HGNPSC₄) were experimented for the first time as a photothermal (PTT) agent with 61.6% photothermal conversion efficiency, and they generated tunable localized heat more efficiently than bare HGNPs. Moreover, the cavity of SC₄ facilitated the formation of an inclusion complex with folic acid to target the folate receptor expressing cancer cells and imparted enhanced biocompatibility. The as-synthesized TTNDV was demonstrated to be an ideal substrate for surface-enhanced Raman scattering (SERS) to monitor the molecular-level therapeutic progression in cells and a spheroidal model. A significant reduction in the tumor mass with a marked survival benefit was achieved in syngraft murine models through this synergistic photo-chemotherapy. Collectively, this multifunctional nanoplatform offers a robust approach to treat cancer without any scope of generating Dox resistance and off-target toxicity.

Defined Mathematical Relationships Among Cancer Cells Suggest Modular Growth in Tumor Progression and Highlight Developmental Features Consistent With a Para-Embryonic Nature of Cancer

Several similarities between the embryo development and the cancer process suggest the para-embryonic nature of tumors. Starting from an initial cancer stem cell (i-CSC) as a para-embryonic stem cell (p-ESC), a hierarchic sequence of CSCs (CSC1s, CSC2s, CSC3s) and non-CSCs [cancer progenitor cells (CPCs), cancer differentiated cells (CDCs)] would be generated, mimicking an ectopic rudimentary ontogenesis. Such a proposed heterogeneous cell hierarchy within the tumor structure would suggest a tumor growth model consistent with experimental data reported for mammary tumors. By tabulating the theoretical data according to this model, it is possible to identify defined mathematical relationships between cancer cells (CSCs and non-CSCs) that are surprisingly similar to experimental data. Moreover, starting from this model, it is possible to speculate that, during progression, tumor growth would occur in a modular way that recalls the propagation of tumor spheres in vitro. All these considerations favor a comparison among normal blastocysts (as in vitro embryos), initial avascular tumors (as in vivo abnormal blastocysts) and tumor spheres (as in vitro abnormal blastocysts). In conclusion, this work provides further support for the para-embryonic nature of the cancer process, as recently theorized.

Colorectal cysts as a validating tool for CAR therapy

Background

Treatment of cancers has largely benefited from the development of immunotherapy. In particular, Chimeric Antigen Receptor (CAR) redirected T cells have demonstrated impressive efficacy against B-cell malignancies and continuous efforts are made to adapt this new therapy to solid tumors, where the immunosuppressive tumor microenvironment is a barrier for delivery. CAR T-cell validation relies on in vitro functional assays using monolayer or suspension cells and in vivo xenograft models in immunodeficient animals. However, the efficacy of CAR therapies remains difficult to predict with these systems, in particular when challenged against 3D organized solid tumors with highly intricate microenvironment. An increasing number of reports have now included an additional step in the development process in which redirected T cells are tested against tumor spheres.

Results

Here, we report a method to produce 3D structures, or cysts, out of a colorectal cancer cell line, Caco-2, which has the ability to form polarized spheroids as a validation tool for adoptive cell therapy in general. We used CD19CAR T cells to explore this method and we show that it can be adapted to various platforms including high resolution microscopy, bioluminescence assays and high-throughput live cell imaging systems.

Conclusion

We developed an affordable, reliable and practical method to produce cysts to validate therapeutic CAR T cells. The integration of this additional layer between in vitro and in vivo studies could be an important tool in the pre-clinical workflow of cell-based immunotherapy.

Compound-based Chinese medicine formula: From discovery to compatibility mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

Chinese medicine formula (CMF) has a long history of clinical use in the treatment of various diseases under the guidance of traditional Chinese medicine (TCM) theory. The application of CMF can be divided into three levels, crude extracts, homologous compounds mixture, and specific compounds. However, the modern scientific connotation of the CMF theory has not been clarified.

AIM OF THE REVIEW

To critically evaluate the research strategy for the investigation of compound-based CMF (CCMF).

MATERIALS AND METHODS

The related information was collected from the scientific databases, including CNKI, Elsevier, ScienceDirect, PubMed, SpringerLink, Web of Science, and Wiley Online.

RESULTS

The research design including discovery, screening, optimization, pharmacodynamics models, and target research techniques including the targets for compatibility compounds were evaluated. Essentially it has been evaluated that the in vitro multicellular three-dimensional culture or organoid model has been proposed for the optimization model for compatibility research of CCMF. Based on these, the traditional compatibility theory of CMF, such as Monarch-Minister-Assistant-Guide (Jun-Chen-Zuo-Shi in Chinese), can probably be elucidated by the CCMF research.

CONCLUSIONS

CCMF has the clear advantage of providing the exact composition and controllable quality of modern medicines, in addition to having the characteristics of multi-ingredients and multi-targets synergistic effects of TCM. However, CCMF is still associated with challenges which need to be addressed for its future use.

Fluorescence Imaging as a Tool in Preclinical Evaluation of Polymer-Based Nano-DDS Systems Intended for Cancer Treatment

Targeted drug delivery using nano-sized carrier systems with targeting functions to malignant and inflammatory tissue and tailored controlled drug release inside targeted tissues or cells has been and is still intensively studied. A detailed understanding of the correlation between the pharmacokinetic properties and structure of the nano-sized carrier is crucial for the successful transition of targeted drug delivery nanomedicines into clinical practice. In preclinical research in particular, fluorescence imaging has become one of the most commonly used powerful imaging tools. Increasing numbers of suitable fluorescent dyes that are excitable in the visible to near-infrared (NIR) wavelengths of the spectrum and the non-invasive nature of the method have significantly expanded the applicability of fluorescence imaging. This chapter summarizes non-invasive fluorescence-based imaging methods and discusses their potential advantages and limitations in the field of drug delivery, especially in anticancer therapy. This chapter focuses on fluorescent imaging from the cellular level up to the highly sophisticated three-dimensional imaging modality at a systemic level. Moreover, we describe the possibility for simultaneous treatment and imaging using fluorescence theranostics and the combination of different imaging techniques, e.g., fluorescence imaging with computed tomography.

In vitro lung cancer multicellular tumor spheroid formation using a microfluidic device

The purpose of this study was to demonstrate self-organizing in vitro multicellular tumor spheroid (MCTS) formation in a microfluidic system and to observe the behavior of MCTSs under controlled microenvironment. The employed microfluidic system was designed for simple and effective formation of MCTSs by generating nutrient and oxygen gradients. The MCTSs were composed of cancer cells, vascular endothelial cells, and type I collagen matrix to mimic the in vivo tumor microenvironment (TME). Cell culture medium was perfused to the microfluidic device loaded with MCTSs by a passive fluidic pump at a constant flow rate. The dose response to an MMPs inhibitor was investigated to demonstrate the effects of biochemical substances. The result of long-term stability of MCTSs revealed that continuous perfusion of cell culture medium is one of the major factors for the successful MCTS formation. A continuous flow of cell culture medium in the in vitro TME greatly affected both the proliferation of cancer cells in the micro-wells and the sustainability of the endothelial cell-layer integrity in the lumen of microfluidic channels. Addition of MMP inhibitor to the cell culture medium improved the stability of the collagen matrix by preventing the detachment and shrinkage of the collagen matrix surrounding the MCTSs. In summary, the present constant flow assisted microfluidic system is highly advantageous for long-term observation of the MCTS generation, tumorous tissue formation process and drug responses. MCTS formation in a microfluidic system may serve as a potent tool for studying drug screening, tumorigenesis and metastasis.

Cytotoxic activity of the seaweed compound fucosterol, alone and in combination with 5-fluorouracil, in colon cells using 2D and 3D culturing

Colorectal cancer (CRC) is one of the most frequently occurring carcinomas which require effective therapies. Fucosterol is a sterol present in marine brown seaweeds with several biological activities. However, the influence of fucosterol in CRC remains to be determined. Thus, the aim of this study was to examine the anticancer activity of fucosterol alone and in combination with 5-fluorouracil (5-Fu) on two human CRC cell lines (HCT116 and HT29) and compared with cytotoxicity in one normal colon fibroblast cell line (CCD-18co) in monolayer (2D). The effect of fucosterol alone or in combination with 5-Fu was further assessed using HT29 multicellular spheroids (3D). Data demonstrated that fucosterol alone or combined with 5-Fu decreased cell viability in HT29 cells in 2D cultures without inducing cytotoxic in normal colon cells. The combination, fucosterol, and 5-Fu, also inhibited cell proliferation, clonogenic potential and cell migration without producing cell death in 2D. In multicellular spheroids, the combination fucosterol plus 5-Fu at the same concentrations used in 2D was not effective demonstrating that under the tested conditions the 3D model was more resistant than the 2D model. Taken together, these findings suggest that fucosterol might be a promising alternative to enhance the cytotoxic and anti-invasive actions of 5-Fu in colon cancer cells without consequent major adverse effects in normal cells. Our results also reinforce the need to include more complex 3D culture models in the initial stages of drug screening.

6-Methoxyquinoline complexes as lung carcinoma agents: induction of oxidative damage on A549 monolayer and multicellular spheroid model

The aim of this work was to study the antitumor effects and the mechanisms of toxic action of a series of 6-methoxyquinoline (6MQ) complexes in vitro. The Cu(II) and Zn(II) complexes (Cu6MQ and Zn6MQ) are formulated as M(6MQ)₂Cl₂; the Co(II) and Ag(I) compounds (Co6MQ and Ag6MQ) are ionic with formulae [Ag(6MQ)₂]⁺NO₃^- and H(6MQ)⁺[Co(6MQ)Cl₃]^- (where H(6MQ)⁺ is the protonated ligand). We found that the copper complex, outperformed the Co(II), Zn(II) and Ag(I) complexes with a lower IC₅₀ (57.9 µM) in A549 cells exposed for 24 h. Cu6MQ decreased cell proliferation and induced oxidative stress detected with H₂DCFDA at 40 µM, which reduces GSH/GSSG ratio. This redox imbalance induced oxidative DNA damage revealed by the Micronucleus test and the Comet assay, which turned into a cell cycle arrest at G2/M phase and induced apoptosis. In multicellular spheroids, the IC₅₀ values tripled the monolayer model (187.3 µM for 24 h). At this concentration, the proportion of live/dead cells diminished, and the spheroids could not proliferate or invade. Although Zn6MQ also decreased GSH/GSSG ratio from 200 µM and the cytotoxicity is related to oxidative stress, the induction of the hydrogen peroxide levels only doubled the control value. Zn6MQ induced S phase arrest, which relates with the increased micronucleus frequency and with the induction of necrosis. Finally, our results reveal a synergistic activity with a 1:1 ratio of both complexes in the monolayer and multicellular spheroids.

Recent Advances in Catalyzed Sequential Reactions and the Potential Use of Tetrapyrrolic Macrocycles as Catalysts

Complexes of porphyrins and of other similar tetrapyrrolic macrocycles are extensively explored as catalysts for different chemical processes, and the development of solid catalysts for heterogeneous processes using molecules with the ability to act as multifunctional catalysts in one-pot reactions is increasing and can lead to the wider use of this class of molecules as catalysts. This mini review focuses on the application of this class of complexes as catalysts in a variety of sequential one-pot reactions.

A novel binuclear hydrazone-based Cd(II) complex is a strong pro-apoptotic inducer with significant activity against 2D and 3D pancreatic cancer stem cells

A novel binuclear Cd complex (1) with hydrazone-based ligand was prepared and characterized by spectroscopy and single crystal X-ray diffraction techniques. Complex 1 reveals a strong pro-apoptotic activity in both human, mammary adenocarcinoma cells (MCF-7) and pancreatic AsPC-1 cancer stem cells (CSCs). While apoptosis undergoes mostly caspase-independent, 1 stimulates the activation of intrinsic pathway with noteworthy down regulation of caspase-8 activity in respect to non-treated controls. Distribution of cells over mitotic division indicates that 1 caused DNA damage in both cell lines, which is confirmed in DNA interaction studies. Compared to 1, cisplatin (CDDP) does not achieve cell death in 2D cultured AsPC-1 cells, while induces different pattern of cell cycle changes and caspase activation in 2D cultured MCF-7 cells, implying that these two compounds do not share similar mechanism of action. Additionally, 1 acts as a powerful inducer of mitochondrial superoxide production with dissipated trans-membrane potential in the majority of the treated cells already after 6 h of incubation. On 3D tumors, 1 displays a superior activity against CSC model, and at 100 μM induces disintegration of spheroids within 2 days of incubation. Fluorescence spectroscopy, along with molecular docking show that compound 1 binds to the minor groove of DNA. Compound 1 binds to the human serum albumin (HSA) showing that the HSA can effectively transport and store 1 in the human body. Thus, our current study strongly supports further investigations on antitumor activity of 1 as a drug candidate for the treatment of highly resistant pancreatic cancer.

Comparative study of the therapeutic effect of Doxorubicin and Resveratrol combination on 2D and 3D (spheroids) cell culture models

The assessment of drug-combinations for pancreatic cancer treatment is usually performed in 2D cell cultures. In this study, the therapeutic effect and the synergistic potential of a particular drug-combination towards 2D and 3D cell cultures of pancreatic cancer were compared for the first time. Thus, the effect of Doxorubicin:Resveratrol (DOX:RES) combinations (at molar ratios ranging from 5:1 to 1:5) in the viability of PANC-1 cells cultured as 2D monolayers and as 3D spheroids was analyzed. The results showed that the cells' viability was more affected when DOX:RES combinations containing higher contents of RES (1:2-1:5 molar ratios) were used. This can be explained by the ability of RES to reduce the P-glycoprotein (P-gp)-mediated efflux of DOX. Further, it was also revealed that the synergic effect of this drug combination was different in 2D and in 3D cell cultures. In fact, despite of the 1:4 and 1:5 DOX:RES ratios being both synergistic for both types of PANC-1 cell cultures, their Combination Indexes (CI) in the monolayers were lower than those attained in spheroids. Overall, the obtained results revealed that the DOX:RES combination is promising for pancreatic cancer treatment and corroborate the emergent need to evaluate drug combinations in 3D cell cultures.

Polyethylene glycol molecular weight influences the ClearT2 optical clearing method for spheroids imaging by confocal laser scanning microscopy

Some fluorescence microscopy techniques, such as confocal laser scanning microscopy (CLSM), have a limited penetration depth. Consequently, the visualization and imaging of three-dimensional (3-D) cell cultures, such as spheroids, using these methods can be a significant challenge. Therefore, to improve the imaging of 3-D tissues, optical clearing methods have been optimized to render transparency to the opaque spheroids. The influence of the polyethylene glycol (PEG) molecular weight (MW) used in the ClearT2 method for the imaging of propidium iodide (PI)-stained spheroids was investigated. The results demonstrated that the ClearT2 clearing method contributes to spheroids transparency and to the preservation of PI fluorescence intensity for all the PEG MW used (4000, 8000, and 10,000 Da). Furthermore, the ClearT2 method performed using PEG 4000 Da allowed a better PI signal penetration depth and cross-section depth. Overall, the optimization of PEG MW can improve the imaging of intact spheroids by CLSM. Furthermore, this work may also contribute to increase the application of 3-D cell culture models by the pharmaceutical industry for the high-throughput screening of therapeutics.

Black bean peptides inhibit glucose uptake in Caco-2 adenocarcinoma cells by blocking the expression and translocation pathway of glucose transporters

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Common bean protein fractions decreased glucose uptake in colorectal cancer cells.

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Protein fractions decreased SGLT1 and GLUT2 gene and protein expression and translocation.

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Black bean protein fractions could be used as anticancer drug adjuvants.

The objective was to evaluate the effect of black bean protein fraction (PFRA), and its derived peptides on glucose uptake, SGLT1 and GLUT2 expression and translocation on Caco-2 cells. The effect of treatments was evaluated on glucose uptake, protein expression and localization and gene expression on Caco-2 cells. PFRA (10 mg/mL) lowered glucose uptake from 27.4% after 30 min to 33.9% after 180 min of treatment compared to untreated control (p < 0.05). All treatments lowered GLUT2 expression after 30 min of treatment compared to untreated control (31.4 to 48.6%, p < 0.05). Similarly, after 24 h of treatment, GLUT2 was decreased in all treatments (23.5% to 48.9%) (p < 0.05). SGLT1 protein expression decreased 18.3% for LSVSVL (100 μM) to 45.1% for PFRA (10 mg/mL) after 24 h. Immunofluorescence microscopy showed a decrease in expression and membrane translocation of GLUT2 and SGLT1 for all treatments compared to untreated control (p < 0.05). Relative gene expression of SLC2A2 (GLUT2) and SLC5A1 (SGLT1) was downregulated significantly up to two-fold change compared to the untreated control after 24 h treatment. Black bean protein fractions are an inexpensive, functional ingredient with significant biological potential to reduce glucose uptake and could be used as an adjuvant in the treatment of colorectal cancer.

The Current Landscape of 3D In Vitro Tumor Models: What Cancer Hallmarks Are Accessible for Drug Discovery?

Cancer prognosis remains a lottery dependent on cancer type, disease stage at diagnosis, and personal genetics. While investment in research is at an all-time high, new drugs are more likely to fail in clinical trials today than in the 1970s. In this review, a summary of current survival statistics in North America is provided, followed by an overview of the modern drug discovery process, classes of models used throughout different stages, and challenges associated with drug development efficiency are highlighted. Then, an overview of the cancer hallmarks that drive clinical progression is provided, and the range of available clinical therapies within the context of these hallmarks is categorized. Specifically, it is found that historically, the development of therapies is limited to a subset of possible targets. This provides evidence for the opportunities offered by novel disease-relevant in vitro models that enable identification of novel targets that facilitate interactions between the tumor cells and their surrounding microenvironment. Next, an overview of the models currently reported in literature is provided, and the cancer biology they have been used to explore is highlighted. Finally, four priority areas are suggested for the field to accelerate adoption of in vitro tumour models for cancer drug discovery.

β1 integrin-mediated multicellular resistance in hepatocellular carcinoma through activation of the FAK/Akt pathway

Objective

To explore the role and mechanism of β1 integrin in the regulation of multicellular drug resistance in hepatocellular carcinoma (HCC).

Methods

This in vitro study used a liquid overlay technique to obtain multicellular spheroids of two human HCC cell lines, HepG2 and Bel-7402. The morphology of the spheroids was observed by optical and electron microscopy. The effects of exposure to 5-fluorouracil (5-FU) and cisplatin (CDDP) on cell proliferation and the induction of apoptosis were assessed in monolayer cells and multicellular spheroids. The levels of β1 integrin and the effects on the focal adhesion kinase (FAK)/protein kinase B (Akt) pathway were evaluated using Western blot analysis, immunofluorescence and flow cytometry. The role of β1 integrin was confirmed by using an inhibitory antibody.

Results

Cell proliferation inhibition and cell apoptosis induced by 5-FUl and CDDP were abrogated in multicellular spheroids compared with monolayer cells. There were high levels of β1 integrin in multicellular spheroids. β1 integrin inhibitory antibody prevented the formation of multicellular spheroids, coupled with a significant increase in proliferation inhibition and apoptosis induction. β1 integrin inhibitory antibody effectively suppressed activation of both FAK and Akt in multicellular spheroids.

Conclusions

β1 integrin mediated multicellular drug resistance through the FAK/Akt pathway in HCC spheroids.

Therapeutic nanosystems co-deliver anticancer drugs and oncogene SiRNA to achieve synergetic precise cancer chemo-gene therapy

Herein we design a therapeutic nanoplatform as carriers of oncogene siRNA and chemotherapeutics to achieve precise cancer therapy.

Poly(HydroxyButyrate-co-HydroxyValerate) (PHBHV) Nanocarriers for Silymarin Release as Adjuvant Therapy in Colo-rectal Cancer

The aim of this study was to address one of the major challenges of the actual era of nanomedicine namely, the bioavailability of poorly water soluble drugs such as Silymarin. We developed new, biodegradable, and biocompatible nanosized shuttles for Silymarin targeted delivery in colon-cancer cells. The design of these 100 nm sized carrier nanoparticles was based on natural polymers and their biological properties such as cellular uptake potential, cytotoxicity and 3D penetrability were tested using a colon cancer cell line (HT-29) as the in vitro culture model. Comparative scanning electron microscopy (SEM) and atomic force microscopy (AFM) measurements demonstrated that the Silymarin loaded Poly(3-HydroxyButyrate-co-3-HydroxyValerate) (PHBHV) nanocarriers significantly decreased HT-29 cells viability after 6 and 24 h of treatment. Moreover, in vivo-like toxicity studies on multicellular tumor spheroids showed that the Silymarin loaded PHBHV nanocarriers are able to penetrate 3D micro tumors and significantly reduce their size.

Colon Cancer Cells Gene Expression Signature As Response to 5- Fluorouracil, Oxaliplatin, and Folinic Acid Treatment

5-FU cytotoxicity mechanism has been assigned both to the miss-incorporation of fluoronucleotides into RNA and DNA and to the inhibition of thymidylate synthase. 5-FU is one of the most widely used chemotherapeutic drugs, although it has severe side effects that may vary between patients. Pharmacogenetic studies related to 5-FU have been traditionally focused on the rate-limiting catabolic enzyme, dihydropyrimidine dehydrogenase that breaks 80–85% of 5-FU into its inactive metabolite. Choosing the right dosing scheme and chemotherapy strategy for each individual patient remains challenging for personalized chemotherapy management. In the general effort toward reduction of colorectal cancer mortality, in vitro screening studies play a very important role. To accelerate translation research, increasing interest has been focused on using in vivo-like models such as three-dimensional spheroids. The development of higher throughput assays to quantify phenotypic changes in spheroids is an active research area. Consequently, in this study we used the microarray technology to reveal the HT-29 colorectal adenocarcinoma cells gene expression signature as response to 5-FU/OXP/FA treatment in a state of the art 3D culture system. We report here an increased reactive oxygen species production under treatment, correlated with a decrease in cell viability and proliferation potential. With respect to the HT-29 cells gene expression under the treatment with 5-FU/OXP/FA, we found 15.247 genes that were significantly differentially expressed (p < 0.05) with a fold change higher that two-fold. Among these, 7136 genes were upregulated and 8111 genes were downregulated under experimental conditions as compared to untreated cells. The most relevant and statistic significant (p < 0.01) pathways in the experiment are associated with the genes that displayed significant differential expression and are related to intracellular signaling, oxidative stress, apoptosis, and cancer.