Generation and initial characterization of novel tumour organoid models to study human pancreatic cancer-induced cachexia

Application of organoids in otolaryngology: head and neck surgery

PURPOSE

The purpose of this review is to systematically summarize the application of organoids in the field of otolaryngology and head and neck surgery. It aims to shed light on the current advancements and future potential of organoid technology in these areas, particularly in addressing challenges like hearing loss, cancer research, and organ regeneration.

METHODS

Review of current literature regrading organoids in the field of otolaryngology and head and neck surgery.

RESULTS

The review highlights several advancements in the field. In otology, the development of organoid replacement therapies offers new avenues for treating hearing loss. In nasal science, the creation of specific organoid models aids in studying nasopharyngeal carcinoma and respiratory viruses. In head and neck surgery, innovative approaches for squamous cell carcinoma prediction and thyroid regeneration using organoids have been developed.

CONCLUSION

Organoid research in otolaryngology-head and neck surgery is still at an early stage. This review underscores the potential of this technology in advancing our understanding and treatment of various conditions, predicting a transformative impact on future medical practices in these fields.

Pancreatic Tumor Organoid-Derived Factors from Cachectic Patients Disrupt Contractile Smooth Muscle Cells

Patients with pancreatic cancer often suffer from cachexia and experience gastrointestinal symptoms that may be related to intestinal smooth muscle cell (SMC) dysfunction. We hypothesized that pancreatic tumor organoids from cachectic patients release factors that perturb the SMC's contractile characteristics. Human visceral SMCs were exposed to conditioned medium (CM) from the pancreatic tumor organoid cultures of cachectic (n = 2) and non-cachectic (n = 2) patients. Contractile proteins and markers of inflammation, muscle atrophy, and proliferation were evaluated by qPCR and Western blot. SMC proliferation and migration were monitored by live cell imaging. The Ki-67-positive cell fraction was determined in the intestinal smooth musculature of pancreatic cancer patients. CM from the pancreatic tumor organoids of cachectic patients did not affect IL-1β, IL-6, IL-8, MCP-1, or Atrogin-1 expression. However, CM reduced the α-SMA, γ-SMA, and SM22-α levels, which was accompanied by a reduced SMC doubling time and increased expression of S100A4, a Ca2+-binding protein associated with the synthetic SMC phenotype. In line with this, Ki-67-positive nuclei were increased in the intestinal smooth musculature of patients with a low versus high L3-SMI. In conclusion, patient-derived pancreatic tumor organoids release factors that compromise the contractile SMC phenotype and increase SMC proliferation. This may contribute to the frequently observed gastrointestinal motility problems in these patients.

Leukemia inhibitory factor suppresses hepatic de novo lipogenesis and induces cachexia in mice

Cancer cachexia is a systemic metabolic syndrome characterized by involuntary weight loss, and muscle and adipose tissue wasting. Mechanisms underlying cachexia remain poorly understood. Leukemia inhibitory factor (LIF), a multi-functional cytokine, has been suggested as a cachexia-inducing factor. In a transgenic mouse model with conditional LIF expression, systemic elevation of LIF induces cachexia. LIF overexpression decreases de novo lipogenesis and disrupts lipid homeostasis in the liver. Liver-specific LIF receptor knockout attenuates LIF-induced cachexia, suggesting that LIF-induced functional changes in the liver contribute to cachexia. Mechanistically, LIF overexpression activates STAT3 to downregulate PPARα, a master regulator of lipid metabolism, leading to the downregulation of a group of PPARα target genes involved in lipogenesis and decreased lipogenesis in the liver. Activating PPARα by fenofibrate, a PPARα agonist, restores lipid homeostasis in the liver and inhibits LIF-induced cachexia. These results provide valuable insights into cachexia, which may help develop strategies to treat cancer cachexia.

Revolutionizing digestive system tumor organoids research: Exploring the potential of tumor organoids

Digestive system tumors are the leading cause of cancer-related deaths worldwide. Despite ongoing research, our understanding of their mechanisms and treatment remain inadequate. One promising tool for clinical applications is the use of gastrointestinal tract tumor organoids, which serve as an important in vitro model. Tumor organoids exhibit a genotype similar to the patient's tumor and effectively mimic various biological processes, including tissue renewal, stem cell, and ecological niche functions, and tissue response to drugs, mutations, or injury. As such, they are valuable for drug screening, developing novel drugs, assessing patient outcomes, and supporting immunotherapy. In addition, innovative materials and techniques can be used to optimize tumor organoid culture systems. Several applications of digestive system tumor organoids have been described and have shown promising results in related aspects. In this review, we discuss the current progress, limitations, and prospects of this model for digestive system tumors.

Antibody-dependent cellular cytotoxicity-inducing antibodies enhance the natural killer cell anti-cancer response against patient-derived pancreatic cancer organoids

Introduction

Pancreatic cancer is associated with poor prognosis, and limited treatment options are available for the majority of patients. Natural killer (NK) cells in combination with antibodies inducing antibody-dependent cell-mediated cytotoxicity (ADCC) could be a highly effective new therapeutic option in pancreatic cancer. Accurate predictive preclinical models are needed to develop successful NK cell immunotherapy. Tumor organoids, in vitro 3D organ-like structures that retain important pathophysiological characteristics of the in vivo tumor, may provide such a model. In the current study, we assessed the cytotoxic potential of adoptive NK cells against human pancreatic cancer organoids. We hypothesized that NK cell anti-tumor responses could be enhanced by including ADCC-triggering antibodies.

Methods

We performed cytotoxicity assays with healthy donor-derived IL-2-activated NK cells and pancreatic cancer organoids from four patients. A 3D cytotoxicity assay using live-cell-imaging was developed and enabled real-time assessment of the response.

Results

We show that NK cells migrate to and target pancreatic cancer organoids, resulting in an increased organoid death, compared to the no NK cell controls (reaching an average fold change from baseline of 2.1±0.8 vs 1.4±0.6). After 24-hours of co-culture, organoid 2D growth increased. Organoids from 2 out of 4 patients were sensitive to NK cells, while organoids from the other two patients were relatively resistant, indicating patient-specific heterogeneity among organoid cultures. The ADCC-inducing antibodies avelumab (anti-PD-L1) and trastuzumab (anti-HER2) increased NK cell-induced organoid cell death (reaching an average fold change from baseline of 3.5±1.0 and 4.5±1.8, respectively). Moreover, combination therapy with avelumab or trastuzumab resulted in complete disintegration of organoids. Finally, inclusion of ADCC-inducing antibodies was able to overcome resistance in NK-organoid combinations with low or no kill.

Discussion

These results support the use of organoids as a relevant and personalized model to study the anti-tumor response of NK cells in vitro and the potential of ADCC-inducing antibodies to enhance NK cell effector function.

Cellular interplay in skeletal muscle regeneration and wasting: insights from animal models

Skeletal muscle wasting, whether related to physiological ageing, muscle disuse or to an underlying chronic disease, is a key determinant to quality of life and mortality. However, cellular basis responsible for increased catabolism in myocytes often remains unclear. Although myocytes represent the vast majority of skeletal muscle cellular population, they are surrounded by numerous cells with various functions. Animal models, mostly rodents, can help to decipher the mechanisms behind this highly dynamic process, by allowing access to every muscle as well as time-course studies. Satellite cells (SCs) play a crucial role in muscle regeneration, within a niche also composed of fibroblasts and vascular and immune cells. Their proliferation and differentiation is altered in several models of muscle wasting such as cancer, chronic kidney disease or chronic obstructive pulmonary disease (COPD). Fibro-adipogenic progenitor cells are also responsible for functional muscle growth and repair and are associated in disease to muscle fibrosis such as in chronic kidney disease. Other cells have recently proven to have direct myogenic potential, such as pericytes. Outside their role in angiogenesis, endothelial cells and pericytes also participate to healthy muscle homoeostasis by promoting SC pool maintenance (so-called myogenesis-angiogenesis coupling). Their role in chronic diseases muscle wasting has been less studied. Immune cells are pivotal for muscle repair after injury: Macrophages undergo a transition from the M1 to the M2 state along with the transition between the inflammatory and resolutive phase of muscle repair. T regulatory lymphocytes promote and regulate this transition and are also able to activate SC proliferation and differentiation. Neural cells such as terminal Schwann cells, motor neurons and kranocytes are notably implicated in age-related sarcopenia. Last, newly identified cells in skeletal muscle, such as telocytes or interstitial tenocytes could play a role in tissular homoeostasis. We also put a special focus on cellular alterations occurring in COPD, a chronic and highly prevalent respiratory disease mainly linked to tobacco smoke exposure, where muscle wasting is strongly associated with increased mortality, and discuss the pros and cons of animal models versus human studies in this context. Finally, we discuss resident cells metabolism and present future promising leads for research, including the use of muscle organoids.

Tumor organoid biobank-new platform for medical research

Organoids are a new type of 3D model for tumor research, which makes up for the shortcomings of cell lines and xenograft models, and promotes the development of personalized precision medicine. Long-term culture, expansion and storage of organoids provide the necessary conditions for the establishment of biobanks. Biobanks standardize the collection and preservation of normal or pathological specimens, as well as related clinical information. The tumor organoid biobank has a good quality control system, which is conducive to the clinical transformation and large-scale application of tumor organoids, such as disease modeling, new drug development and high-throughput drug screening. This article summarized the common tumor types of patient-derived organoid (PDO) biobanks and the necessary information for biobank construction, such as the number of organoids, morphology, success rate of culture and resuscitation, pathological types. In our results, we found that patient-derived tumor organoid (PDTO) biobanks were being established more and more, with the Netherlands, the United States, and China establishing the most. Biobanks of colorectal, pancreas, breast, glioma, and bladder cancers were established more, which reflected the relative maturity of culture techniques for these tumors. In addition, we provided insights on the precautions and future development direction of PDTO biobank building.

Exosomal IL-8 derived from Lung Cancer and Colon Cancer cells induced adipocyte atrophy via NF-κB signaling pathway

BACKGROUND

Cytokines secreted in the tumor microenvironment function in cancer cachexia (CC), a common clinicopathological syndrome associated with adipocyte wasting and skeletal muscle atrophy. Extracellular vesicles (EVs) secreted by cancer cells actively engage in inter-tissue communication; EVs and enclosed cytokines are largely undefined in CC adipocytes wasting.

METHODS

EVs derived from Lewis lung carcinoma (LLC) and colorectal cancer C26 cells were extracted and characterized. Conditioned medium and EVs from cancer cells were applied to 3 T3-L1 adipocytes. Recombinant IL-8, IL-8 neutralizing antibody, CXCR2 and NF-κB inhibitor were examined in functional assays. Lipolysis of adipocytes was monitored by Western blots, Oil red O staining and glycerol assays. Furthermore, LLC and C26 cell lines were established as cachexia model to explore the relevance of IL-8 and NF-κB signaling in CC adipose wasting. Adipose tissues were collected for histology analyses.

RESULTS

LLC and C26 cell-derived EVs induced lipolysis of 3 T3-L1 adipocytes. Specially, Dil-labeled EVs were effectively taken up by 3 T3-L1 adipocytes, which were motivated by the delivered IL-8 to elicit the NF-κB pathway. In comparison, special IL-8 neutralizing antibody relieved that lipolysis of 3 T3-L1 adipocytes induced by EVs together with conditioned medium of LLC and C26 cells, respectively. Consistently, both CXCR2 and NF-κB inhibitors would lessen the phenotype of lipolysis in 3 T3-L1 adipocytes. In the in vivo settings, both LLC and C26-tumor bearing mice had higher serum IL-8 levels as compared to the control groups. Two typical lipolysis markers, PGC1α and UCP1, were also up-regulated in the adipose tissues of LLC and C26-tumor mice groups, respectively.

CONCLUSIONS

EVs secreted by LLC and C26 tumor cells would induce adipocyte wasting via extracellular IL-8-mediated NF-κB signaling. Our study pointed out the physiological and therapeutic values of exosomal IL-8 in CC lipolysis.

Review of the endocrine organ-like tumor hypothesis of cancer cachexia in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal types of solid tumors, associated with a high prevalence of cachexia (~80%). PDAC-derived cachexia (PDAC-CC) is a systemic disease involving the complex interplay between the tumor and multiple organs. The endocrine organ-like tumor (EOLT) hypothesis may explain the systemic crosstalk underlying the deleterious homeostatic shifts that occur in PDAC-CC. Several studies have reported a markedly heterogeneous collection of cachectic mediators, signaling mechanisms, and metabolic pathways, including exocrine pancreatic insufficiency, hormonal disturbance, pro-inflammatory cytokine storm, digestive and tumor-derived factors, and PDAC progression. The complexities of PDAC-CC necessitate a careful review of recent literature summarizing cachectic mediators, corresponding metabolic functions, and the collateral impacts on wasting organs. The EOLT hypothesis suggests that metabolites, genetic instability, and epigenetic changes (microRNAs) are involved in cachexia development. Both tumors and host tissues can secrete multiple cachectic factors (beyond only inflammatory mediators). Some regulatory molecules, metabolites, and microRNAs are tissue-specific, resulting in insufficient energy production to support tumor/cachexia development. Due to these complexities, changes in a single factor can trigger bi-directional feedback circuits that exacerbate PDAC and result in the development of irreversible cachexia. We provide an integrated review based on 267 papers and 20 clinical trials from PubMed and ClinicalTrials.gov database proposed under the EOLT hypothesis that may provide a fundamental understanding of cachexia development and response to current treatments.

Chemosensitivity of 3D Pancreatic Cancer Organoids Is Not Affected by Transformation to 2D Culture or Switch to Physiological Culture Medium

Organoids are increasingly used to investigate patient-specific drug responsiveness, but organoid culture is complex and expensive, and carried out in rich, non-physiological media. We investigated reproducibility of drug-responsiveness of primary cell cultures in 2D versus 3D and in conventional versus physiological cell culture medium. 3D pancreatic ductal adenocarcinoma organoid cultures PANCO09b and PANCO11b were converted to primary cell cultures growing in 2D. Transformed 2D cultures were grown in physiological Plasmax medium or Advanced-DMEM/F12. Sensitivity towards gemcitabine, paclitaxel, SN-38, 5-fluorouacil, and oxaliplatin was investigated by cell viability assays. Growth rates of corresponding 2D and 3D cultures were comparable. PANCO09b had a shorter doubling time in physiological media. Chemosensitivity of PANCO09b and PANCO11b grown in 2D or 3D was similar, except for SN-38, to which PANCO11b cultured in 3D was more sensitive (2D: 8.2 ×10^-3 ± 2.3 ×10^-3 vs. 3D: 1.1 ×10^-3 ± 0.6 ×10^-3, p = 0.027). PANCO09b and PANCO11b showed no major differences in chemosensitivity when cultured in physiological compared to conventional media, although PANCO11b was more sensitive to SN-38 in physiological media (9.8 × 10^-3 ± 0.7 × 10^-3 vs. 5.2 × 10^-3 ± 1.8 × 10^-3, p = 0.015). Collectively, these data indicate that the chemosensitivity of organoids is not affected by culture medium composition or culture dimensions. This implies that organoid-based drug screens can be simplified to become more cost-effective.

The Molecular Basis and Therapeutic Potential of Leukemia Inhibitory Factor in Cancer Cachexia

Simple Summary

The mechanism of cancer cachexia is linked to a variety of factors, and inflammatory factors are thought to play a key role. We summarize the main roles of LIF in the development of cancer cachexia, including promoting fat loss, inducing skeletal muscle atrophy and causing anorexia nervosa. The main aim of this review is to increase the understanding of the effects of LIF in cachexia and to provide new insights into the treatment of cancer cachexia.

Abstract

Cachexia is a chronic metabolic syndrome that is characterized by sustained weight and muscle mass loss and anorexia. Cachexia can be secondary to a variety of diseases and affects the prognosis of patients significantly. The increase in inflammatory cytokines in plasma is deeply related to the occurrence of cachexia. As a member of the IL-6 cytokine family, leukemia inhibitory factor (LIF) exerts multiple biological functions. LIF is over-expressed in the cancer cells and stromal cells of various tumors, promoting the malignant development of tumors via the autocrine and paracrine systems. Intriguingly, increasing studies have confirmed that LIF contributes to the progression of cachexia, especially in patients with metastatic tumors. This review combines all of the evidence to summarize the mechanism of LIF-induced cachexia from the following four aspects: (i) LIF and cancer-associated cachexia, (ii) LIF and alterations of adipose tissue in cachexia, (iii) LIF and anorexia nervosa in cachexia, and (iv) LIF and muscle atrophy in cachexia. Considering the complex mechanisms in cachexia, we also focus on the interactions between LIF and other key cytokines in cachexia and existing therapeutics targeting LIF.

3D bioprinted white adipose model for in vitro study of cancer-associated cachexia induced adipose tissue remodeling

Cancer-associated cachexia (CAC) is a complex metabolic and behavioral syndrome with multiple manifestations that involve systemic inflammation, weight loss, and adipose lipolysis. It impacts the quality of life of patients and is the direct cause of death in 20-30% of cancer patients. The severity of fat loss and adipose tissue remodeling negatively correlate with patients' survival outcomes. To address the mechanism of fat loss and design potential approaches to prevent the process, it will be essential to understand CAC pathophysiology through white adipose tissue models. In the present study, an engineered human white adipose tissue (eWAT) model based on three-dimensional (3D) bioprinting was developed and treated with pancreatic cancer cell-conditioned medium (CM) to mimic the status of CAC in vitro. We found that the CM treatment significantly increased the lipolysis and accumulation of the extracellular matrix (ECM). The 3D eWATs were further vascularized to study the influence of vascularization on lipolysis and CAC progression, which was largely unknown. Results demonstrated that CM treatment improved the angiogenesis of vascularized eWATs (veWATs), and veWATs demonstrated decreased glycerol release but increased Ucp1 expression, compared to eWATs. Many unique inflammatory cytokines (IL-8, CXCL-1, GM-CSF, etc) from the CM were detected and supposed to contribute to eWAT lipolysis, Ucp1 up-regulation, and ECM development. In response to CM treatment, eWATs also secreted inflammatory adipokines related to the metastatic ability of cancer, muscle atrophy, and vascularization (NGAL, CD54, IGFBP-2, etc). Our work demonstrated that the eWAT is a robust model for studying cachectic fat loss and the accompanying remodeling of adipose tissue. It is therefore a useful tool for future research exploring CAC physiologies and developing potential therapies.

Human pancreatic tumour organoid-derived factors enhance myogenic differentiation

BACKGROUND

Most patients with pancreatic cancer develop cachexia, which is characterized by progressive muscle loss. The mechanisms underlying muscle loss in cancer cachexia remain elusive. Pancreatic tumour organoids are 3D cell culture models that retain key characteristics of the parent tumour. We aimed to investigate the effect of pancreatic tumour organoid-derived factors on processes that determine skeletal muscle mass, including the regulation of muscle protein turnover and myogenesis.

METHODS

Conditioned medium (CM) was collected from human pancreatic cancer cell lines (PK-45H, PANC-1, PK-1, and KLM-1), pancreatic tumour organoid cultures from a severely cachectic (PANCO-9a) and a non-cachectic patient (PANCO-12a), and a normal pancreas organoid culture. Differentiating C2C12 myoblasts and mature C2C12 myotubes were exposed to CM for 24 h or maintained in control medium. In myotubes, NF-kB activation was monitored using a NF-κB luciferase reporter construct, and mRNA expression of E3-ubiquitin ligases and REDD1 was analysed by RT-qPCR. C2C12 myoblast proliferation and differentiation were monitored by live cell imaging and myogenic markers and myosin heavy chain (MyHC) isoforms were assessed by RT-qPCR.

RESULTS

Whereas CM from PK-1 and KLM-1 cells significantly induced NF-κB activation in C2C12 myotubes (PK-1: 3.1-fold, P < 0.001; KLM-1: 2.1-fold, P = 0.01), Atrogin-1/MAFbx and MuRF1 mRNA were only minimally and inconsistently upregulated by the CM of pancreatic cancer cell lines. Similarly, E3-ubiquitin ligases and REDD1 mRNA expression in myotubes were not altered by exposure to pancreatic tumour organoid CM. Compared with the control condition, CM from both PANCO-9a and PANCO-12a tumour organoids increased proliferation of myoblasts, which was accompanied by significant downregulation of the satellite cell marker paired-box 7 (PAX7) (PANCO-9a: -2.1-fold, P < 0.001; PANCO-12a: -2.0-fold, P < 0.001) and myogenic factor 5 (MYF5) (PANCO-9a: -2.1-fold, P < 0.001; PANCO-12a: -1.8-fold, P < 0.001) after 48 h of differentiation. Live cell imaging revealed accelerated alignment and fusion of myoblasts exposed to CM from PANCO-9a and PANCO-12a, which was in line with significantly increased Myomaker mRNA expression levels (PANCO-9a: 2.4-fold, P = 0.001; PANCO-12a: 2.2-fold, P = 0.004). These morphological and transcriptional alterations were accompanied by increased expression of muscle differentiation markers such as MyHC-IIB (PANCO-9a: 2.5-fold, P = 0.04; PANCO-12a: 3.1-fold, P = 0.006). Although the impact of organoid CM on myogenesis was not associated with the cachexia phenotype of the donor patients, it was specific for tumour organoids, as CM of control pancreas organoids did not modulate myogenic fusion.

CONCLUSIONS

These data show that pancreatic tumour organoid-derived factors alter the kinetics of myogenesis, which may eventually contribute to impaired muscle mass maintenance in cancer cachexia.

3D and organoid culture in research: physiology, hereditary genetic diseases and cancer

In nature, cells reside in tissues subject to complex cell–cell interactions, signals from extracellular molecules and niche soluble and mechanical signaling. These microenvironment interactions are responsible for cellular phenotypes and functions, especially in normal settings. However, in 2D cultures, where interactions are limited to the horizontal plane, cells are exposed uniformly to factors or drugs; therefore, this model does not reconstitute the interactions of a natural microenvironment. 3D culture systems more closely resemble the architectural and functional properties of in vivo tissues. In these 3D cultures, the cells are exposed to different concentrations of nutrients, growth factors, oxygen or cytotoxic agents depending on their localization and communication. The 3D architecture also differentially alters the physiological, biochemical, and biomechanical properties that can affect cell growth, cell survival, differentiation and morphogenesis, cell migration and EMT properties, mechanical responses and therapy resistance. This latter point may, in part, explain the failure of current therapies and affect drug discovery research. Organoids are a promising 3D culture system between 2D cultures and in vivo models that allow the manipulation of signaling pathways and genome editing of cells in a body-like environment but lack the many disadvantages of a living system. In this review, we will focus on the role of stem cells in the establishment of organoids and the possible therapeutic applications of this model, especially in the field of cancer research.

GDF15, an emerging key player in human aging

Growth differentiation factor 15 (GDF15) is recently emerging not only as a stress-related mitokine, but also as a key player in the aging process, being one of the most up-regulated protein with age and associated with a variety of age-related diseases (ARDs). Many data indicate that GDF15 has protective roles in several tissues during different stress and aging, thus playing a beneficial role in apparent contrast with the observed association with many ARDs. A possible detrimental role for this protein is then hypothesized to emerge with age. Therefore, GDF15 can be considered as a pleiotropic factor with beneficial activities that can turn detrimental in old age possibly when it is chronically elevated. In this review, we summarize the current knowledge on the biology of GDF15 during aging. We also propose GDF15 as a part of a dormancy program, where it may play a role as a mediator of defense processes aimed to protect from inflammatory damage and other stresses, according to the life history theory.

Neoantigen Quantity and Quality in Relation to Pancreatic Cancer Survival

Introduction

Factors underlying antitumor immunity in pancreatic cancer (PC) are poorly understood. We hypothesized that not neoantigen quantity, but quality, is related to immune cell infiltration and survival.

Methodology

We performed genomic and transcriptomic profiling of paired normal, tumor tissue of 13 patients with PC with distinct survival times. Additionally, neoantigens prediction and immunological profiling were performed.

Results

The proportion of neoantigens with a low similarity-to-self score was higher in short-term survivors (p < 0.0001), while mutational load and burden, similarity-to-known-pathogens, and immunogenicity of neoantigens were not associated with immune cell infiltration or survival.

Discussion

No tumor mutational load or neoantigen quantity, but low similarity-to-self score, was associated with immune cell infiltration and survival.

Preparing ductal epithelial organoids for high-spatial-resolution molecular profiling using mass spectrometry imaging

Organoid culture systems are self-renewing, three-dimensional (3D) models derived from pluripotent stem cells, adult derived stem cells or cancer cells that recapitulate key molecular and structural characteristics of their tissue of origin. They generally form into hollow structures with apical-basolateral polarization. Mass spectrometry imaging (MSI) is a powerful analytical method for detecting a wide variety of molecules in a single experiment while retaining their spatiotemporal distribution. Here we describe a protocol for preparing organoids for MSI that (1) preserves the 3D morphological structure of hollow organoids, (2) retains the spatiotemporal distribution of a vast array of molecules (3) and enables accurate molecular identification based on tandem mass spectrometry. The protocol specifically focuses on the collection and embedding of the organoids in gelatin, and gives recommendations for MSI-specific sample preparation, data acquisition and molecular identification by tandem mass spectrometry. This method is applicable to a wide range of organoids from different origins, and takes 1 d from organoid collection to MSI data acquisition.

Ovarian cancer ascites induces skeletal muscle wasting in vitro and reflects sarcopenia in patients

BACKGROUND

Cachexia-associated skeletal muscle wasting or 'sarcopenia' is highly prevalent in ovarian cancer and contributes to poor outcome. Drivers of cachexia-associated sarcopenia in ovarian cancer remain elusive, underscoring the need for novel and better models to identify tumour factors inducing sarcopenia. We aimed to assess whether factors present in ascites of sarcopenic vs. non-sarcopenic ovarian cancer patients differentially affect protein metabolism in skeletal muscle cells and to determine if these effects are correlated to cachexia-related patient characteristics.

METHODS

Fifteen patients with an ovarian mass and ascites underwent extensive physical screening focusing on cachexia-related parameters. Based on computed tomography-based body composition imaging, six cancer patients were classified as sarcopenic and six were not; three patients with a benign condition served as an additional non-sarcopenic control group. Ascites was collected, and concentrations of cachexia-associated factors were assessed by enzyme-linked immunosorbent assay. Subsequently, ascites was used for in vitro exposure of C2C12 myotubes followed by measurements of protein synthesis and breakdown by radioactive isotope tracing, qPCR-based analysis of atrophy-related gene expression, and NF-κB activity reporter assays.

RESULTS

C2C12 protein synthesis was lower after exposure to ascites from sarcopenic patients (sarcopenia 3.1 ± 0.1 nmol/h/mg protein vs. non-sarcopenia 5.5 ± 0.2 nmol/h/mg protein, P < 0.01), and protein breakdown rates tended to be higher (sarcopenia 31.2 ± 5.2% vs. non-sarcopenia 20.9 ± 1.9%, P = 0.08). Ascites did not affect MuRF1, Atrogin-1, or REDD1 expression of C2C12 myotubes, but NF-κB activity was specifically increased in cells exposed to ascites from sarcopenic patients (sarcopenia 2.2 ± 0.4-fold compared with control vs. non-sarcopenia 1.2 ± 0.2-fold compared with control, P = 0.01). Protein synthesis and breakdown correlated with NF-κB activity (r_s  = -0.60, P = 0.03 and r_s  = 0.67, P = 0.01, respectively). The skeletal muscle index of the ascites donors was also correlated to both in vitro protein synthesis (r_s  = 0.70, P = 0.005) and protein breakdown rates (r_s  = -0.57, P = 0.04).

CONCLUSIONS

Ascites of sarcopenic ovarian cancer patients induces pronounced skeletal muscle protein metabolism changes in C2C12 cells that correlate with clinical muscle measures of the patient and that are characteristic of cachexia. The use of ascites offers a new experimental tool to study the impact of both tumour-derived and systemic factors in various cachexia model systems, enabling identification of novel drivers of tissue wasting in ovarian cancer.

Patient-derived organoids as a model for tumor research

Cancer represents a leading cause of death, despite the rapid progress of cancer research, leading to urgent need for accurate preclinical model to further study of tumor mechanism and accelerate translational applications. Cancer cell lines cannot fully recapitulate tumors of different patients due to the lack of tumor complexity and specification, while the high technical difficulty, long time, and substantial cost of patient-derived xenograft model makes it unable to be used extensively for all types of tumors and large-scale drug screening. Patient-derived organoids can be established rapidly with a high success rate from many tumors, and precisely replicate the key histopathological, genetic, and phenotypic features, as well as therapeutic response of patient tumor. Therefore, they are extensively used in cancer basic research, biobanking, disease modeling and precision medicine. The combinations of cancer organoids with other advanced technologies, such as 3D bio-printing, organ-on-a-chip, and CRISPR-Cas9, contributes to the more complete replication of complex tumor microenvironment and tumorigenesis. In this review, we discuss the various methods of the establishment and the application of patient-derived organoids in diverse tumors as well as the limitations and future prospects of these models. Further advances of tumor organoids are expected to bridge the huge gap between bench and bedside and provide the unprecedented opportunities to advance cancer research.

Organoids as research models for hepatocellular carcinoma

Organoid culture is an emerging research tool that has proved tremendously useful in a multitude of aspects, one of which is cancer research. They largely overcome the limitations of previous cancer models by their faithful recapitulation of the in vivo biology, while still remaining amenable to perturbations. Using a cocktail of biologicals that mimic the stem cell niche signaling, hepatocellular carcinoma (HCC) organoids could be generated from tissue samples of both human and murine origin. Existing reports show that HCC organoids retain key characteristics of their parental tumor tissue, including the histological architecture, genomic landscape, expression profile and intra-tumor heterogeneity. There is ongoing effort to establish living biobanks of patient-derived cancer organoids, annotated with multi-omics data and clinical data, and they can be particularly valuable in stratification of HCC subtypes, pre-clinical drug discovery and personalized medicine. In the future, efforts in the standardization of procedures and nomenclature, refinement of protocols, as well as engineering of the culture systems will enable scientists to unleash the full potential of organoid technology.

Tumor organoids: synergistic applications, current challenges, and future prospects in cancer therapy

Patient-derived cancer cells (PDCs) and patient-derived xenografts (PDXs) are often used as tumor models, but have many shortcomings. PDCs not only lack diversity in terms of cell type, spatial organization, and microenvironment but also have adverse effects in stem cell cultures, whereas PDX are expensive with a low transplantation success rate and require a long culture time. In recent years, advances in three-dimensional (3D) organoid culture technology have led to the development of novel physiological systems that model the tissues of origin more precisely than traditional culture methods. Patient-derived cancer organoids bridge the conventional gaps in PDC and PDX models and closely reflect the pathophysiological features of natural tumorigenesis and metastasis, and have led to new patient-specific drug screening techniques, development of individualized treatment regimens, and discovery of prognostic biomarkers and mechanisms of resistance. Synergistic combinations of cancer organoids with other technologies, for example, organ-on-a-chip, 3D bio-printing, and CRISPR-Cas9-mediated homology-independent organoid transgenesis, and with treatments, such as immunotherapy, have been useful in overcoming their limitations and led to the development of more suitable model systems that recapitulate the complex stroma of cancer, inter-organ and intra-organ communications, and potentially multiorgan metastasis. In this review, we discuss various methods for the creation of organ-specific cancer organoids and summarize organ-specific advances and applications, synergistic technologies, and treatments as well as current limitations and future prospects for cancer organoids. Further advances will bring this novel 3D organoid culture technique closer to clinical practice in the future.

Magnetic Fluid Hyperthermia as Treatment Option for Pancreatic Cancer Cells and Pancreatic Cancer Organoids

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is a cancer with a meager prognosis due to its chemotherapy resistance. A new treatment method may be magnetic fluid hyperthermia (MFH). Magnetoliposomes (ML), consisting of superparamagnetic iron oxide nanoparticles (SPION) stabilized with a phospholipid-bilayer, are exposed to an alternating magnetic field (AMF) to generate heat. To optimize this therapy, we investigated the effects of MFH on human PDAC cell lines and 3D organoid cultures.

MATERIAL AND METHODS

ML cytotoxicity was tested on Mia PaCa-2 and PANC-1 cells and on PDAC 3D organoid cultures, generated from resected tissue of patients. The MFH was achieved by AMF application with an amplitude of 40-47 kA/m and a frequency of 270 kHz. The MFH effect on the cell viability of the cell lines and the organoid cultures was investigated at two different time points. Clonogenic assays evaluated the impairment of colony formation. Altering ML set-ups addressed differences arising from intra- vs extracellular ML locations.

RESULTS

Mia PaCa-2 and PANC-1 cells showed no cytotoxic effects at ML concentrations up to 300 µg(Fe)/mL and 225 µg(Fe)/mL, respectively. ML at a concentration of 225 µg(Fe)/mL were also non-toxic for PDAC organoid cultures. MFH treatment using exclusively extracellular ML presented the highest impact on cell viability. Clonogenic assays demonstrated remarkable impairment as long-term outcome in MFH-treated PDAC cell lines. Additionally, we successfully treated PDAC organoids with extracellular ML-derived MFH, resulting in notably reduced cell viabilities 2h and 24 h post treatment. Still, PDAC organoids seem to partly recover from MFH after 24 h as opposed to conventional 2D-cultures.

CONCLUSION

Treatment with MFH strongly diminished pancreatic cancer cell viability in vitro, making it a promising treatment strategy. As organoids resemble the more advanced in vivo conditions better than conventional 2D cell lines, our organoid model holds great potential for further investigations.

Generation and initial characterization of novel tumour organoid models to study human pancreatic cancer-induced cachexia

BACKGROUND

The majority of patients with pancreatic cancer develops cachexia. The mechanisms underlying cancer cachexia development and progression remain elusive, although tumour-derived factors are considered to play a major role. Pancreatic tumour organoids are in vitro three-dimensional organ-like structures that retain many pathophysiological characteristics of the in vivo tumour. We aimed to establish a pancreatic tumour organoid biobank from well-phenotyped cachectic and non-cachectic patients to enable identification of tumour-derived factors driving cancer cachexia.

METHODS

Organoids were generated from tumour tissue of eight pancreatic cancer patients. A comprehensive pre-operative patient assessment of cachexia-related parameters including nutritional status, physical performance, body composition, and inflammation was performed. Tumour-related and cachexia-related characteristics of the organoids were analysed using histological stainings, targeted sequencing, and real-time-quantitative PCR. Cachexia-related factors present in the circulation of the patients and in the tumour organoid secretome were analysed by enzyme-linked immunosorbent assay.

RESULTS

The established human pancreatic tumour organoids presented typical features of malignancy corresponding to the primary tumour (i.e. nuclear enlargement, multiple nucleoli, mitosis, apoptosis, and mutated KRAS and/or TP53). These tumour organoids also expressed variable levels of many known cachexia-related genes including interleukin-6 (IL-6), TNF-α, IL-8, IL-1α, IL-1β, Mcp-1, GDF15, and LIF. mRNA expression of IL-1α and IL-1β was significantly reduced in organoids from cachectic vs. non-cachectic patients (IL-1α: -3.8-fold, P = 0.009, and IL-1β: -4.7-fold, P = 0.004). LIF, IL-8, and GDF15 mRNA expression levels were significantly higher in organoids from cachectic vs. non-cachectic patients (LIF: 1.6-fold, P = 0.003; IL-8: 1.4-fold, P = 0.01; GDF15: 2.3-fold, P < 0.001). In line with the GDF15 and IL-8 mRNA expression levels, tumour organoids from cachectic patients secreted more GDF15 and IL-8 compared with organoids from non-cachectic patients (5.4 vs. 1.5 ng/mL, P = 0.01, and 7.4 vs. 1.3 ng/mL, P = 0.07, respectively).

CONCLUSIONS

This novel human pancreatic tumour organoid biobank provides a valuable tool to increase our understanding of the mechanisms driving cancer cachexia. Our preliminary characterization of the secretome of these organoids supports their application in functional studies including conditioned medium approaches and in vivo transplantation models.