Study Tumor Biology Research Articles

Xenopus laevis (Daudin, 1802) as a Model Organism for Bioscience: A Historic Review and Perspective.

In vitro systems have been mainly promoted by authorities to sustain research by following the 3Rs principle, but continuously increasing amounts of evidence point out that in vivo experimentation is also of extreme relevance. Xenopus laevis, an anuran amphibian, is a significant model organism in the study of evolutionary developmental biology, toxicology, ethology, neurobiology, endocrinology, immunology and tumor biology; thanks to the recent development of genome editing, it has also acquired a relevant position in the field of genetics. For these reasons, X. laevis appears to be a powerful and alternative model to the zebrafish for environmental and biomedical studies. Its life cycle, as well as the possibility to obtain gametes from adults during the whole year and embryos by in vitro fertilization, allows experimental studies of several biological endpoints, such as gametogenesis, embryogenesis, larval growth, metamorphosis and, of course, the young and adult stages. Moreover, with respect to alternative invertebrate and even vertebrate animal models, the X. laevis genome displays a higher degree of similarity with that of mammals. Here, we have reviewed the main available literature on the use of X. laevis in the biosciences and, inspired by Feymann's revised view, "Plenty of room for biology at the bottom", suggest that X. laevis is a very useful model for all possible studies.

BIOL-11. PRECLINICAL MODELLING OF PEDIATRIC BRAIN TUMORS USING ORGANOID TECHNOLOGY

Abstract Molecular characterization has resulted in improved classification of pediatric brain tumors, leading to many novel (sub)types with distinct oncodriving events. To study tumor biology and to perform translational research on each of these tumors, preclinical models are essential. However, we are currently lacking sufficient models, especially in vitro, to represent each (sub)type and their heterogeneity. To generate large series of preclinical in vitro models for pediatric brain tumors, we are using organoid technology. Cells from patient samples and patient-derived xenograft samples have been taken into culture to establish 3D organoids using tumor type specific culture conditions. These organoid lines retain the molecular characteristics of the original tumor tissue. They can be used to perform high-throughput drug screens, genetic manipulations, and co-cultures with, for instance, immune cells. Viable tissue is not always available for all tumor (sub)types and specific oncodrivers. To circumvent this lack of tissue, we can also induce tumors in vitro. Therefore, we generate cerebral and cerebellar brain organoids from human pluripotent stem cells. These organoids mimic human developing brain cells and can be genetically manipulated to model different brain tumor types. These genetically engineered brain tumor models allow us to study the cellular origins of pediatric brain tumors and the different tumor driving mechanisms. Tumors induced in the brain organoids histologically and molecularly resemble human patient samples based on (single cell) transcriptomic analyses. Moreover, the tumor cells are able to establish xenografts in mouse brains. In summary, organoid technology provides a novel avenue to establish in vitro models for pediatric brain tumors. At the meeting we will present data for various new ependymoma, medulloblastoma and embryonal brain tumor organoid models.

Applications and Advances of Multicellular Tumor Spheroids: Challenges in Their Development and Analysis.

Biomedical research requires both in vitro and in vivo studies in order to explore disease processes or drug interactions. Foundational investigations have been performed at the cellular level using two-dimensional cultures as the gold-standard method since the early 20th century. However, three-dimensional (3D) cultures have emerged as a new tool for tissue modeling over the last few years, bridging the gap between in vitro and animal model studies. Cancer has been a worldwide challenge for the biomedical community due to its high morbidity and mortality rates. Various methods have been developed to produce multicellular tumor spheroids (MCTSs), including scaffold-free and scaffold-based structures, which usually depend on the demands of the cells used and the related biological question. MCTSs are increasingly utilized in studies involving cancer cell metabolism and cell cycle defects. These studies produce massive amounts of data, which demand elaborate and complex tools for thorough analysis. In this review, we discuss the advantages and disadvantages of several up-to-date methods used to construct MCTSs. In addition, we also present advanced methods for analyzing MCTS features. As MCTSs more closely mimic the in vivo tumor environment, compared to 2D monolayers, they can evolve to be an appealing model for in vitro tumor biology studies.

Abstract 4708: Application of spatially resolved transcriptomics to screen multiple tumor biospecimens using tissue microarrays

Abstract The tumor microenvironment is composed of highly heterogeneous structures and cell types that dynamically influence and communicate with each other. Although examination of singular biospecimens is sufficient for diagnostic purposes, it is inadequate and cost prohibitive when scaling for complex and overarching studies. Thus, high density multi-tumor tissue microarrays (TMAs) have been a practical and effective solution for high-throughput molecular analysis of tissues. Introduced more than a decade ago, TMAs have been instrumental in the recent study of tumor biology, the development of diagnostic tests, the establishment of quality control, and the investigation and identification of oncological biomarkers. Here, we demonstrate the pairing of the 10x Genomics Visium Cytassist Spatial Gene Expression Solution and Xenium In-Situ Platform on multi-tumor TMAs to screen for common biomarkers among a cohort of samples. Spatial transcriptomics technology has proven valuable in mapping the whole transcriptome with spatial context (Visium), whereas In Situ (Xenium) enables high-throughput cellular characterization at single-cell resolution. With the addition of our CytAssist platform, we expand on the pre-existing standard Visium solution by facilitating the retrieval of RNA transcriptomic information from tissues placed on standard or archival slides. On the other hand, the novel Xenium platform compliments whole transcriptome Visium data by unlocking the potential to assign transcripts to a particular cell with spatial context and subcellular resolution. The combination of spatial transcriptomics and targeted in situ data with FFPE TMAs promotes a high-throughput method to accelerate the uncovering of molecular signatures suitable to understanding the tumor microenvironment. We showcase the ability to spatially and comprehensively resolve individual oncogene and tumor suppressor genes associated with multiple tumors from a cohort of cancer patients and from multiple different tumor samples. In addition, these markers are mapped back to distinct morphological features within each tissue core, and use differential gene expression data to identify distinct cell types throughout the different patient tissues. By combining the throughput of TMA samples and depth of the Visium and Xenium platforms, the strategy enables greater insights into cell-type specifics while also expanding the spectrum of biospecimen types that can be analyzed. Citation Format: Syrus Mohabbat, Hardeep Singh, Stephen R. Williams, Lauren M M. Gutgesell, David J. Sukovich, Govinda M. Kamath, Hanyoup Kim, Amanda Janesick, Robert Shelansky, Ghezal Beliakoff, Augusto M. Tentori, Albert Kim, Cedric R. Uytingco, Sarah Taylor. Application of spatially resolved transcriptomics to screen multiple tumor biospecimens using tissue microarrays. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4708.

Abstract 34: A clinically-relevant orthotopic endometrial carcinosarcoma mouse model using human patient-derived organoids

Abstract Uterine carcinosarcoma (CS) is a rare but aggressive endometrial malignancy. Like the other subtypes of endometrial cancer, the incidence of CS has been increasing and it is projected to continue to rise. Additionally, there is racial disparity seen in African American women diagnosed with CS. African American women have an increased incidence of CS compared to other racial/ethnic groups. They also have an overall increased mortality related to endometrial cancer. Compared to other histologic subtypes of endometrial cancer, CS remains rare and understudied on a molecular and cellular basis. It remains under-represented in clinical trials. Therefore, the current therapies available for CS are extrapolated from those treatments used in the other subtypes of endometrial cancer. There is a paucity of data surrounding targeted therapies for CS resulting in worse outcomes for patients who are diagnosed with this aggressive and lethal cancer. We have developed a clinically relevant, orthotopic CS murine injection model by injecting human CS patient-derived organoids (PDO) from diverse ancestries into the endometrium of immunocompromised mice. Tumor progression in the mice was monitored with physical examination, PET/CT scan, contrast enhanced CT scan, and ultrasound. The tumor was established after three months and was visualized using various imaging techniques. The mice were sacrificed and the diagnosis of invasive CS was confirmed by macroscopic, histologic and genomic analyses. Our orthotopic CS PDO transplantation model has many potential applications for studying tumor biology and the response to treatment for CS in the pre-clinical setting. This may help identify targeted therapy for CS and potentially advance to Phase 1 human clinical trials. Citation Format: Arielle Katcher, Charlie Chung, Megan Gorman, Brian Yueh, Scott Lyons, Joseph Merrill, Libia Garcia, Marina Frimer, Gary L. Goldberg, Semir Beyaz. A clinically-relevant orthotopic endometrial carcinosarcoma mouse model using human patient-derived organoids [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 34.

Medulloblastoma: The latest major advances

Medulloblastoma (MB) is a malignant brain tumor that mainly affects children. It is rarely found in adults. Among the four groups of MB defined today according to molecular characteristics, group 3is the least favorable with an overall survival rate of 50%. Current treatments, based on surgery, radiotherapy, and chemotherapy, are not sufficiently adapted to the different characteristics of the four MB groups. However, the use of new cellular and animal models has opened new doors to interesting therapeutic avenues. In this review, we detail recent advances in MB research, with a focus on the genes and pathways that drive tumorigenesis, with particular emphasis on the animal models that have been developed to study tumor biology, as well as advances in new targeted therapies.

Abstract P4-03-05: HER2 + Breast Cancer in Afro-Caribbean Women in New York City

Abstract Background: Human Epidermal Growth Factor receptor 2 (HER2) protein overexpression and/or amplification positive breast cancer accounts for 14% of breast cancer cases in the United States. The use of anti-HER2 targeted therapy in combination with chemotherapy has resulted in better response rates leading to better outcomes in patients with this breast cancer subtype. Few studies directly investigate breast cancer outcomes in Afro-Caribbean women in the U.S, and fewer studies have investigated HER2 positive (HER2+) disease in this patient group. We describe the clinicopathologic characteristics and outcomes of HER2+ breast cancer in this minority patient group. Methods: This is a retrospective study conducted at Kings County Hospital (KCH), a public hospital in Brooklyn, a New York City borough with the highest population of Afro-Caribbeans in the United States, outside of Miami, Florida. Data of patients diagnosed with breast cancer from 2015-2018 was collected from the hospital’s tumor registry. Clinical and pathologic data was collected and analyzed with descriptive statistics and Chi-square testing. Results: A total of 299 women with breast cancer were screened and 18% (54) had HER2+ disease. 63% (34) of these patients were post-menopausal, with median age 56. 78% self-identified as Afro-Caribbean. 19% (11) of patients reported first- or second-degree relatives with a breast cancer diagnosis, 22% (13) reported first-degree relative with non-breast malignancy. Half of the patients younger < 45 years age reported a positive family history of any type of cancer. 74% of patients presented with Nottingham Grade 3 disease, 31% with localized disease, without lymph node involvement, 52% with regional lymph node involvement, and 17% with distant metastasis. 63% of patients were estrogen receptor (ER) positive and 37% were ER negative. Post-menopausal women presented with higher rates of lymph node involvement at 70.4% vs. 50% in pre-menopausal women (p=0.17). 41% (22) of patients received neoadjuvant chemotherapy while 31% received adjuvant therapy with standard chemotherapy and anti-HER2 targeted treatment. Of the 22 patients who received neoadjuvant treatment, 14% had complete pathologic response, 68% had partial response, and 18% had disease progression. Treatment response to neoadjuvant therapy was independent of lymph node status (90.9% in local disease vs. 85.7% in lymph node involvement, p=0.66). The median progression free survival was 48 months, overall survival at 7 years was not reached, and mortality rate was 16.7%. Conclusions: In our analysis, Afro-Caribbean patients with HER2+ breast cancer presented with high grade tumor, high incidence of regional lymph node involvement, and ER positive tumors. Noteworthy was the presence of strong family history of cancers, suggestive of familial or inherited cancers. Pathologic complete response to neoadjuvant chemotherapy was remarkably less than anticipated, and further research is warranted to study tumor biology and responses to standard HER2 systemic therapies in these patients.

Oxidative DNA damage in reconstituting T cells is associated with relapse and inferior survival after allo-SCT

AbstractAllogeneic hematopoietic stem cell transplantation (allo-SCT) is the only curative treatment option for a number of hematologic malignancies. Its therapeutic potential relies on the potency of donor T cells to eliminate residual malignant cells, the so-called graft-versus-leukemia (GVL) effect. Disease relapse remains the most frequent treatment failure and is associated with poor outcome. Therefore, it is inevitable to decipher mechanisms that weaken GVL. In recent years, studies of tumor biology have revealed that metabolic remodeling of the micromilieu can critically regulate immune responses. Accumulation of reactive oxygen species leads to a metabolic condition known as oxidative stress, which can severely hamper T cells. Currently, only a few studies, mainly using preclinical models, have demonstrated the occurrence of oxidative stress after allo-SCTs. Therefore, we sought to investigate oxidative stress in a well-characterized group of patients who underwent allo-SCT and its impact on reconstituting T cells. We identified high concentrations of serum 8-hydroxydeoxyguanosine (8-OHdG) as an established biomarker for oxidative stress. 8-OHdG is one of the major products of DNA oxidation, which is normally rapidly removed. After allo-SCT, T cells accumulated oxidative DNA damage. High cellular 8-OHdG content (8-OHdGhi) was associated not only with signs of enhanced T-cell activation but also premature exhaustion. The inability of 8-OHdGhi T cells to efficiently target malignant cells or produce cytotoxic granzyme B and interferon gamma was associated with a significantly increased relapse risk and a shorter overall survival. Taken together, our novel findings could give reason to focus on bolstering DNA repair in reconstituting T cells as a means to improve GVL efficacy.

Nafamostat Mesylate in Combination with the Mouse Amino-Terminal Fragment of Urokinase-Human Serum Albumin Improves the Treatment Outcome of Triple-Negative Breast Cancer Therapy.

Triple-negative breast cancer (TNBC) is highly aggressive and causes a higher proportion of metastatic cases. However, therapies directed to specific molecular targets have rarely achieved clinically meaningful improvements in the outcome of TNBC therapy. A urokinase-type plasminogen activator (uPA), one of the best-validated biomarkers of breast cancer, is an extracellular proteolytic serine protease involved in many pathological and physiological processes, including tumor cell invasion and metastasis. Nafamostat mesylate (NM) is a synthetic compound that inhibits various serine proteases and has been used as a therapeutic agent for the treatment of TNBC. Nevertheless, NM has poor specificity for serine proteases and is easy be hydrolyzed; moreover, the inhibitory mechanism of TNBC therapy is unclear. In this study, we combine NM with a macromolecular drug delivery vehicle, mouse amino-terminal fragment of urokinase-human serum albumin (mATF-HSA), to form a complex (mATF-HSA:NM) using the dilution-incubation-purification method. mATF specifically targets uPAR overexpressed on the surface of TNBC cells; moreover, HSA prevents NM from being hydrolyzed by numerous serine proteases. mATF-HSA:NM showed stronger inhibitory effects on the proliferation and metastasis of TNBC in vitro and in vivo without significant cytotoxicity on normal cells and tissues. In addition, we demonstrated that NM mediates metastasis of TNBC cells through inhibition of uPA using a stable uPA knockdown cell line (MDA-MB231 shuPA). Overall, we have developed a macromolecular complex targeted to treat high uPAR-expressing tumor types, and mATF-HSA can potentially be used to load other types of drugs with tumor-targeting specificity for mouse tumor models and is a promising tool to study tumor biology in mouse tumor models.

Targeted therapy in oncology

The aim of the review is to highlight the principle of action, effectiveness and prospects for the development of targeted therapy in the treatment of patients with malignant neoplasms based on recent clinical studies. Thanks to the active study of tumor biology, specific target molecules have been discovered and it has become possible to target tumor cells with targeted drugs. Today, targeted drugs are used in the treatment of malignant tumors of various organs and continue to demonstrate their effectiveness, improve overall survival and progression-free time, compared with previous standards of treatment.

Characterizing the biology of primary brain tumors and their microenvironment via single-cell profiling methods.

Genomic and transcriptional heterogeneity is prevalent among the most common and aggressive primary brain tumors in children and adults. Over the past 20 years, advances in bioengineering, biochemistry and bioinformatics have enabled the development of an array of techniques to study tumor biology at single-cell resolution. The application of these techniques to study primary brain tumors has helped advance our understanding of their intra-tumoral heterogeneity and uncover new insights regarding their co-option of developmental programs and signaling from their microenvironment to promote tumor proliferation and invasion. These insights are currently being harnessed to develop new therapeutic approaches. Here we provide an overview of current single-cell techniques and discuss relevant biology and therapeutic insights uncovered by their application to primary brain tumors in children and adults.

Advances in 3D Bioprinting for Cancer Biology and Precision Medicine: From Matrix Design to Application.

The tumor microenvironment is highly complex owing to its heterogeneous composition and dynamic nature. This makes tumors difficult to replicate using traditional 2D cell culture models that are frequently used for studying tumor biology and drug screening. This often leads to poor translation of results between in vitro and in vivo and is reflected in the extremely low success rates of new candidate drugs delivered to the clinic. Therefore, there has been intense interest in developing 3D tumor models in the laboratory that are representative of the in vivo tumor microenvironment and patient samples. 3D bioprinting is an emerging technology that enables the biofabrication of structures with the virtue of providing accurate control over distribution of cells, biological molecules, and matrix scaffolding. This technology has the potential to bridge the gap between in vitro and in vivo by closely recapitulating the tumor microenvironment. Here, a brief overview of the tumor microenvironment is provided and key considerations in biofabrication of tumor models are discussed. Bioprinting techniques and choice of bioinks for both natural and synthetic polymers are also outlined. Lastly, current bioprinted tumor models are reviewed and the perspectives of how clinical applications can greatly benefit from 3D bioprinting technologies are offered.

Abstract 6141: Understanding the role of gp78 in breast cancer health disparities

Abstract Background: Breast cancer is a devastating disease where death rates for women of African ancestry (AA) are 40% higher than that of European ancestry (EA), demonstrating racial disparity in mortality. gp78 protein is an independent predictor of poor outcomes in women of AA that is over-expressed in aggressive breast cancers. The purpose of this research was to understand how gp78 is associated with poor survival rates by studying tumor biology and gene expression. We hypothesize a positive correlation between the overexpression of gp78 protein in higher amounts for AA women than that of European ancestry women which may correlate with specific functional pathways. Methods: Medical data was collected from a health disparities cohort in Eastern North Carolina. The patient’s race, ethnicity/ancestry were self-reported at the initial visit; the study cohort was reported as 50% AA. Immunohistochemistry to measure protein expression, DNA mutation & gene expression used with Gene Set Enrichment Analysis(GSEA) of 147 patients to identify functional pathway differences in tumor biology between high versus low gp78 expression versus gp78 expression based on patient race. Hierarchical clustered heatmaps were used to compare overlapping genes that were differentially expressed. Results: 49 common genes were identified as the overlap between the genes in the differential gene expression list for gp78 and the two different gene set enrichment analyses compared: GSEA based on patients expressing high versus low gp78 protein by IHC versus GSEA based on white vs black patients (race). The hierarchical cluster analysis of the gene expression patterns identified two prominent clusters: association by extracellular factors in the tumor microenvironment and association by mitochondrial regulation and proliferation. Conclusions: This study suggests that gp78 differences based on race may be linked to tumor microenvironment, mitochondrial function, & proliferation linking gp78 as a biomarker that is differentially expressed based on race and more highly correlated with breast cancer aggressiveness to functional properties of mitochondrial metabolism & tumor microenvironment. We will explore this gene signature/biomarker that may predict survival based on race. This discovery provides new areas of research to explore the relationship of extracellular factors in the tumor microenvironment, mitochondria regulation, & proliferation. Clinical & nonclinical interventions addressing racial health disparity in mortality should target breast cancer-specific health determinants (both environmental and biological) among those of AA with efforts to decrease racial disparities in mortality rates. These new observations indicate gp78 may be a biomarker that can predict survival based on race using tumor biology, which can contribute to new strategies for reducing the rate at which women of AA disproportionately suffer from breast cancer mortality. Citation Format: Sediqua Sherese Bufford. Understanding the role of gp78 in breast cancer health disparities [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6141.

MODL-10. Tumor-brain-organoids as a model for pediatric brain tumors research

Abstract BACKGROUND: Embryonal brain neoplasms like atypical teratoid rhabdoid tumor (ATRT) or embryonal tumor with multilayered rosettes (ETMR) still have a very poor outcome despite intensive treatment including chemotherapy, irradiation and surgery. To date, precision oncology has identified clinically relevant innovative therapeutic targets only for a minor subpopulation of pediatric brain tumor patients, which may be due to current in vitro screens not recapitulating the cellular heterogeneity and cellular interactions in vivo. As cellular heterogeneity and cellular interactions majorly influence the response of tumor cells to treatment, we established an innovative 3D screening platform that combines human neural tissue surrounding primary tumor tissue. METHODS: We established a model of tumor-brain-organoids (TBO) by incorporating embryonal tumor cells (ATRT and ETMR tumor cells) into hiPSC-derived forebrain organoids. Using whole mount immunostaining (WMI), we evaluated cancer-phenotype, the neuronal and progenitor cell distribution in brain organoids, and we performed drug screening analysis. Furthermore, we used single-cell RNA-sequencing to characterize the cellular heterogeneity and the effect of tumor-organoid cell-cell communication on transcriptional programs. RESULTS: ATRT as well as ETMR tumor cells incorporated extensively into the organoid tissue. We observed remarkable differences in the invasiveness of ATRT-MYC cells into TBO in comparison with ATRT-SHH and ETMR cells via high content imaging. Moreover, tumor cells affected the gene expression of different cell types of the organoid by upregulating genes of important signaling/growth related pathways (e. g. MAP2K2, IGFBP2) and epigenetic regulators (like BRD7). Screening through a 300 compound FDA-approved drug library in these TBO, we identified potential innovative therapeutic approaches against these embryonal tumors. CONCLUSION: Tumor-brain-organoids can be used as a platform to study tumor biology, tumor interactions with its neural tissue microenvironment, as well as for high-throughput drug and toxicity screening in pediatric brain tumor precision oncology.

Patient-Derived Bladder Cancer Organoid Models in Tumor Biology and Drug Testing: A Systematic Review.

Simple SummaryPrimary culture of cancer cells from patient tumors in a physiologically relevant system can provide information about tumor biology, disentangle the role of different cell types within the tumors, and give information about drug sensitivity for the development of cancer-targeted therapies and precision medicine. This requires the use of well-characterized and easily expandable tumor models. This review focuses on 3D models developed from primary human tissue including normal urothelium or bladder cancer samples, the characteristics of the models, and to what extent the organoids represent the diversity observed among human tumors.Bladder cancer is a common and highly heterogeneous malignancy with a relatively poor outcome. Patient-derived tumor organoid cultures have emerged as a preclinical model with improved biomimicity. However, the impact of the different methods being used in the composition and dynamics of the models remains unknown. This study aims to systematically review the literature regarding patient-derived organoid models for normal and cancer tissue of the bladder, and their current and potential future applications for tumor biology studies and drug testing. A PRISMA-compliant systematic review of the PubMED, Embase, Web of Sciences, and Scopus databases was performed. The results were analyzed based on the methodologies, comparison with primary tumors, functional analysis, and chemotherapy and immunotherapy testing. The literature search identified 536 articles, 24 of which met the inclusion criteria. Bladder cancer organoid models have been increasingly used for tumor biology studies and drug screening. Despite the heterogeneity between methods, organoids and primary tissues showed high genetic and phenotypic concordance. Organoid sensitivity to chemotherapy matched the response in patient-derived xenograft (PDX) models and predicted response based on clinical and mutation data. Advances in bioengineering technology, such as microfluidic devices, bioprinters, and imaging, are likely to further standardize and expand the use of organoids.

In vitro 3D cocultured tumor-vascular barrier model based on alginate hydrogel and Transwell system for anti-cancer drug evaluation

The development of three-dimensional (3D) in vitro model to recapitulate the in vivo tumor tissue is essential for studying tumor biology, discovering anti-cancer drugs, and evaluating anti-cancer drug efficacy. However, most of the previous models lack the involvement of vascular barrier. Here, we proposed an in vitro 3D cocultured tumor-vascular barrier model by the combination of alginate hydrogels beads and Transwell system. PC-3 cells and NIH/3T3 cells were encapsulated in alginate hydrogel beads, which were cultured in the bottom chamber of Transwell, while human umbilical vein endothelial cells (HUVECs) were cultured on the porous membrane in the upper chamber to form vascular barrier. The effect of the concentration of alginate sodium on the morphology, diameter and swelling ratio of the beads was studied. The alginate sodium content and cell seeding density were further optimized according to cell proliferation ability. The formation of endothelial barrier was verified by immunostaining with tight junction protein VE-cadherin and transendothelial electrical resistance (TEER) monitoring. Finally, the drug response of 3D cocultured tumor-vascular barrier model to curcumin was evaluated. Compared with two-dimensional (2D) coculture model and 3D coculture spheroid model, 3D tumor-vascular barrier model showed the highest activity of cancer cells and the strongest drug resistance. The developed 3D cocultured tumor-vascular barrier model possesses great potential to be applied for in vitro evaluation of anti-tumor drugs.

CD44 related stemness maneuvers oral squamous cell carcinoma biology.

Despite the commendable advancements in oral squamous cell carcinoma (OSCC) diagnostics and therapeutics, it remains a considerable medical challenge. Recent evidence suggests that small populations of stem-like cancer cells are responsible for tumor initiation, progression and metastasis. These cancer stem cells (CSCs) have been identified and characterized in various types of cancers, including OSCCs. CSC hypothesis has been supported by the expression of CD44, CD133, ALDH1 and ABCG2. Amongst them, CD44 (a transmembrane glycoprotein), is the most reported CSC marker in OSCCs. The increasing incidence of OSCC combined with its poor survival rates motivates a need for research into the expression of adhesion molecules and may play a pivotal role in studying tumor biology related to invasion and distant metastasis. To quantify the expression of CD44 in the different grades of OSCC and to correlate the expression of CD44 with clinicopathological parameters. A total of 20 formalin-fixed paraffin-embedded tissues of OSCC were retrieved from department archives. Immunohistochemical staining was performed using anti-CD44 antibody (Biogenex). The expression was assessed semi-quantitatively in varying histopathological grades of OSCC and were correlated with tumor, node, metastasis (TNM) staging which were obtained from the department records. The results were statistically evaluated. Overexpression of CD44 was detected in 48% of well-differentiated OSCCs followed by a linear decrease in moderately differentiated and poorly differentiated OSCCs and the expression correlated with the tumor size (T) in 23% cases and with lymph node metastases (N) in 42% of cases (P ≤0.05). The results of the present study suggested an altered expression of CD44 in OSCC. This depicts an association of CD44 with tumor aggressiveness and Epithelial Mesenchymal Transition (EMT) related to loss of cell adhesion in a subset of OSCC-clearly stating tumor cell stemness as a key factor in malignant potential of OSCC.

Three-Dimensional Cell Culture Models of Hepatocellular Carcinoma - a Review.

Three-dimensional (3D) cell culture studies are becoming extremely common because of theircapability to mimic tumor architecture, such as cell-cell and cell-ECM interactions, more efficiently than 2Dmonolayer systems. These interactions have important roles in defining the tumor cell behaviors, such asproliferation, differentiation, and most importantly, tumor drug response. This review aims to provide an overview of the methods for 3D tumor spheroid formation to modelhuman tumors, specifically concentrated on studies using hepatocellular carcinoma (HCC) cells. We obtained information from previously published articles. In this review, there is discussion of thescaffold and non-scaffold-based approaches, including hanging drop, bioreactors and 3D bioprinting. The mimicking of the tumor microenvironment (TME) as tumor spheroids could provide avaluable platform for studying tumor biology. Multicellular tumor spheroids are self-assembled cultures of mixedcells (tumor and stromal cells) organized in a 3D arrangement. These spheroids closely mimic the main features ofhuman solid tumors, such as structural organization, central hypoxia, and overall oxygen and nutrient gradients.Hepatocellular carcinoma (HCC) is the most common liver malignancy, and most difficult to overcome because ofits drug resistance and tumor heterogeneity. In order to mimic this highly heterogeneous environment, 3D cellculture systems are needed.

Object detection for automatic cancer cell counting in zebrafish xenografts.

Cell counting is a frequent task in medical research studies. However, it is often performed manually; thus, it is time-consuming and prone to human error. Even so, cell counting automation can be challenging to achieve, especially when dealing with crowded scenes and overlapping cells, assuming different shapes and sizes. In this paper, we introduce a deep learning-based cell detection and quantification methodology to automate the cell counting process in the zebrafish xenograft cancer model, an innovative technique for studying tumor biology and for personalizing medicine. First, we implemented a fine-tuned architecture based on the Faster R-CNN using the Inception ResNet V2 feature extractor. Second, we performed several adjustments to optimize the process, paying attention to constraints such as the presence of overlapped cells, the high number of objects to detect, the heterogeneity of the cells’ size and shape, and the small size of the data set. This method resulted in a median error of approximately 1% of the total number of cell units. These results demonstrate the potential of our novel approach for quantifying cells in poorly labeled images. Compared to traditional Faster R-CNN, our method improved the average precision from 71% to 85% on the studied data set.

Modeling the Tumor Microenvironment of Ovarian Cancer: The Application of Self-Assembling Biomaterials.

Simple SummaryThe tumor-surrounding niche comprises not only cancer cells but also stromal cells, signaling molecules, secreted factors and the extracellular matrix. This niche has a three-dimensional (3D) architecture and is implicated in tumor progression, metastasis and drug resistance. 3D cancer models have been increasingly attracting attention due to their potential to provide a more representative tumor niche compared to traditional two-dimensional (2D) models. Bioengineered 3D models contain multiple cell types and important molecules that interact with each other to resemble crucial features of tumor tissues, including the 3D architecture, mechanical properties, genetic profile and cell responses to therapeutics. These defined characteristics highlight the application of 3D models to study tumor biology, metastatic pathways and drug resistance.Ovarian cancer (OvCa) is one of the leading causes of gynecologic malignancies. Despite treatment with surgery and chemotherapy, OvCa disseminates and recurs frequently, reducing the survival rate for patients. There is an urgent need to develop more effective treatment options for women diagnosed with OvCa. The tumor microenvironment (TME) is a key driver of disease progression, metastasis and resistance to treatment. For this reason, 3D models have been designed to represent this specific niche and allow more realistic cell behaviors compared to conventional 2D approaches. In particular, self-assembling peptides represent a promising biomaterial platform to study tumor biology. They form nanofiber networks that resemble the architecture of the extracellular matrix and can be designed to display mechanical properties and biochemical motifs representative of the TME. In this review, we highlight the properties and benefits of emerging 3D platforms used to model the ovarian TME. We also outline the challenges associated with using these 3D systems and provide suggestions for future studies and developments. We conclude that our understanding of OvCa and advances in materials science will progress the engineering of novel 3D approaches, which will enable the development of more effective therapies.