Tumor Cells Of Origin Research Articles

MODL-17. OBESOGENIC DIET INCREASES NF1-OPTIC PATHWAY GLIOMA FORMATION THROUGH EFFECTS ON THE TUMOR CELL OF ORIGIN

Abstract Rates of both pediatric low-grade glioma and obesity have been rising in the U.S., and children of obese mothers have increased rates of several tumor types, including brain tumors. Importantly, obesity in the U.S. is largely dietary-driven, given the prevalence of high fat and high sugar (HFHS) diets. High-fat diet exposure can promote proliferation of embryonic neuroglial progenitor cells (NPCs), which animal modeling suggests are potential cells of origin for low-grade glioma. Together, these data suggested that in utero exposure to an obesogenic diet might affect the formation of pediatric brain tumors. Using preclinical models of the Neurofibromatosis type 1 (NF1) cancer predisposition syndrome, in which optic pathway gliomas (Nf1-OPGs) arise from NPCs in the developing third ventricular zone (TVZ), we sought to determine whether maternal obesogenic exposure would increase glioma formation through intrinsic effects on the tumor cell of origin. We demonstrated that progeny from obese dams exposed to HFHS diet during and preceding gestation had increased proliferation and glial differentiation of WT and Nf1-mutant TVZ NPCs. Progeny of non-obese dams exposed to this diet during gestation demonstrate a similar phenotype, suggesting these effects are related to maternal diet rather than weight. Obesogenic diet exposure (Ob) also increased glioma penetrance in two low-penetrance murine models of Nf1-OPG. Moreover, we demonstrated that Ob mice developed earlier tumor onset with elevated Erk activity in a high-penetrance Nf1-OPG model. In contrast, when obesogenic diet was introduced postnatally, only 11% of mice showed accelerated tumor formation. Ob-exposed nerves also displayed elevated levels of activated Stat3, consistent with upregulation of the IL6/Jak/Stat3 pathway with HFHS diet exposure. These findings establish maternal obesogenic diet as a risk for pediatric glioma formation, in part through in utero effects on the tumor cell of origin, and identify the MAPK and IL6/Jak/Stat3 pathways as targets for further investigation.

Plasma-Derived Exosome Proteins as Novel Diagnostic and Prognostic Biomarkers in Neuroblastoma Patients.

Neuroblastoma (NB) is the most common extracranial solid tumor during infancy, causing up to 10% of mortality in children; thus, identifying novel early and accurate diagnostic and prognostic biomarkers is mandatory. NB-derived exosomes carry proteins (Exo-prots) reflecting the status of the tumor cell of origin. The purpose of this study was to characterize, for the first time, the Exo-prots specifically expressed in NB patients associated with tumor phenotype and disease stage. We isolated exosomes from plasma specimens of 24 HR-NB patients and 24 low-risk (LR-NB) patients at diagnosis and of 24 age-matched healthy controls (CTRL). Exo-prot expression was measured by liquid chromatography-mass spectrometry. The data are available via ProteomeXchange (PXD042422). The NB patients had a different Exo-prot expression profile compared to the CTRL. The deregulated Exo-prots in the NB specimens acted mainly in the tumor-associated pathways. The HR-NB patients showed a different Exo-prot expression profile compared to the LR-NB patients, with the modulation of proteins involved in cell migration, proliferation and metastasis. NCAM, NCL, LUM and VASP demonstrated a diagnostic value in discriminating the NB patients from the CTRL; meanwhile, MYH9, FN1, CALR, AKAP12 and LTBP1 were able to differentiate between the HR-NB and LR-NB patients with high accuracy. Therefore, Exo-prots contribute to NB tumor development and to the aggressive metastatic NB phenotype.

SAT553 A Case of Metastatic Functional Papillary Thyroid Cancer in the Setting of Graves’ Disease

Abstract Disclosure: N. Manuel: None. S.J. Sternlieb: None. J. Dendy: None. Q.Z. Iqbal: None. A Case of Metastatic Functional Papillary Thyroid Cancer In the Setting of Graves’ DiseaseManuel, N., Sternlieb, S., Grissett, B., Iqbal, Q., Dendy, J. Background: Grave’s disease (GD) and papillary thyroid cancer (PTC) can be concomitant diseases. We report a rare case of metastatic PTC with concomitant GD leading to symptomatic hyperthyroidism despite total thyroidectomy. Clinical Case: A 58-year-old woman with longstanding history of thyroid nodules and left dominant nodule with benign biopsy on multiple occasions presented to her PCP with dyspnea, weight loss and globus sensation. CT of the chest was obtained revealing tracheal deviation from neck mass, mediastinal lymphadenopathy and multiple pulmonary nodules. Biopsy of lung nodule showed follicular features consistent with tumor cells of thyroid origin. She had a total thyroidectomy with central neck dissection with a final diagnosis of left sided 5 cm infiltrative follicular variant papillary thyroid carcinoma. Thyroid hormone replacement was initiated and on follow up 4 weeks later she was noted to be tachycardic at weight-based dose. At that time TSH was <0.010 uIU/mL (0.400 - 4.00), free T4 was 1.96 ng/dL (0.71 – 1.51) and Thyroglobulin was found to be 31516 ng/dL (Athyrotic <0.1). Prior to planned RAI she developed symptoms of dyspnea on exertion and edema and was sent to the ER for abnormal D. Dimer. Workup for PE was negative including CTA of the chest. A follow up visit showed further symptoms of hyperthyroidism with worsening fatigue, dyspnea, palpitations and new onset tremor. Levothyroxine dose was decreased further but 2 weeks later she returned to the ER with worsened thyroid function tests, and she was admitted for symptomatic hyperthyroidism. Levothyroxine was held and she was placed on PTU and propranolol. Given the overt symptomatic hyperthyroidism there were concerns for either Jod-Basedow phenomenon from iodine load with recent imaging or for hyperfunctioning PTC metastasis as the cause. Thyrotropin receptor antibody level was checked to further clarify and was elevated at 22 IU/L (0.00 – 1.75) consistent with GD. An I-131 diagnostic whole-body scan demonstrated small foci of right thyroid bed remnant and iodine-avid metastases involving mediastinal nodal disease as well as pulmonary and osseous metastases. She then underwent RAI therapy with 104.5 mCi I-131 without Thyrogen stimulation. Follow up whole body scan showed persistence of iodine-avid metastasis without any new foci of uptake compared to pretreatment scans. Conclusion: Although the coexistence of them is rare, GD should be put into the differential of rapidly progressive metastatic PTC especially if patient markedly hyperthyroid on lower doses of thyroid hormone. While functional thyroid carcinoma is rare, with less than 100 cases in literature, thorough investigation should be completed in order to not miss this concomitant disease process. Presentation Date: Saturday, June 17, 2023

FNAC (Fine needle aspiration cytology) and histopathological correlation and reclassification of thyroid neoplasm in accordance with WHO classification 2022

While assessing whether a patient requires surgery or conservative treatment, the thyroid FNAC is crucial. “The Bethesda System of Reporting Thyroid Cytopathology” was introduced to resolve the problem of standardising terminology in Thyroid FNA diagnosis. This study aims to evaluate the histopathological correlation and to also assess the diagnostic accuracy of TBSRTC at an institutional level with respect to histopathology. Additionally, reclassification of these cases in accordance with new Update of WHO Classification of Thyroid tumors 2022.This is a 3-year retrospective study of thyroid lesions from August 2019 to August 2022 comprising of 160 cases. Data was retrieved from institutional database and analysed. Fine needle aspiration Cytology- Histopathological correlation followed by determination of diagnostic accuracy of TBSRTC was done using Sensitivity, Specificity, PPV, NPV and accuracy. Reclassification was done on the 160 histopathological diagnosis based on the new updated classification.Study showed female predominance and largest cohort belonged to the age group of 21–40 years. Cytohistopathological correlation was done and 4 discordant cases were identified. The Sensitivity, Specificity, PPV, NPV and Accuracy was found to be 95.77, 98.87, 98.55%, 96.7% and 97.5% respectively. On reclassification, the tumors were now classified based on cell of origin and maximum no. of cases were identified under the category of Follicular- cell derived.FNAC is a sensitive and specific method of evaluating thyroid lesions. TBSRTC shows excellent diagnostic accuracy in detecting malignant lesions and can be used for screening neoplasm. The new classification demonstrates classification based on tumour cell of origin. It is crucial for Clinicians and Pathologists to be informed of new terminologies and classification schemes to aid more therapeutic options for patients.

BIOL-16. OBESOGENIC DIET EXPOSURE INCREASES NF1-OPTIC PATHWAY GLIOMA FORMATION IN PART THROUGH EFFECTS ON THE CELL OF ORIGIN

Abstract Pediatric low-grade glioma incidence has been rising in the U.S. over the last 20 years, concurrent with a rising rate of obesity in both the adult and pediatric populations. Recently, children of obese mothers have been demonstrated to have increased rates of several tumors, including brain tumors. Importantly, obesity in the U.S. is driven in large part by diet, given the abundance and accessibility of high-fat, high-sugar food choices. High-fat diet exposure has been previously demonstrated to promote proliferation and glial differentiation of embryonic neuroglial progenitor cells (NPCs) around the third ventricular zone (TVZ), suggesting that in utero exposure to an obesogenic diet might affect the formation of pediatric tumors derived from these cells, such as Neurofibromatosis Type 1 (NF1)-related optic pathway glioma (OPG). Based on these data, we hypothesized that maternal obesogenic exposure would increase Nf1-OPG formation through intrinsic effects on the tumor cell of origin. We demonstrated that progeny from obese dams exposed to HFHS diet during and preceding gestation demonstrated increased proliferation and glial differentiation of WT and Nf1-heterozygous TVZ NPCs in vivo. Progeny of non-obese dams exposed to this diet during gestation demonstrated a similar phenotype, suggesting these effects were related to maternal diet rather than weight. We then assessed how obesogenic diet exposure affected tumor formation. We determined that this exposure increases glioma penetrance in two low-penetrance models of NF1-OPG. Finally, we demonstrated that obesogenic diet exposure resulted in earlier tumor onset in a high-penetrance Nf1-OPG model. Taken together, these findings suggest that obesogenic diet exposure increases pediatric glioma formation, in part through effects on the tumor cell of origin while still in utero. It may also have implications for clinical prognosis, as earlier age of tumor onset has been negatively associated with visual outcomes in NF1-OPG.

BIOL-06. UNDERSTANDING OLIGODENDROCYTE PROGENITOR CELL CONTRIBUTION TO GLIOMAGENESIS USING A NOVEL PHARMACOGENETIC ABLATION TOOL

Abstract In the central nervous system (CNS), gliomas represent almost 50% of all pediatric tumors and due to their complex histological and biological heterogeneity, aggressive standard treatment consisting of surgery and chemoradiotherapy remains ineffective. As a result, more biologically based therapies are urgently needed, and this requires a deeper knowledge of the etiology and biology of gliomas and the tumor microenvironment. Oligodendrocyte progenitor cells (OPCs) are a potential origin of human gliomas (as suggested by studies in genetically engineered mouse models) and human OPC-like tumor cells contribute to tumor heterogeneity and malignancy. Resident (non-neoplastic) OPCs have been found to intermix with glioma cells and proliferate within the tumor microenvironment. The significance of the interactions of resident OPCs and glioma cells remains unknown. We hypothesize that resident OPCs functionally integrate into the tumor cell network and affect tumor properties. We have generated a novel mouse model of conditional OPC ablation to overcome methodological challenges of most current approaches that often result in partial and transient OPC ablation, which limits our understanding of long-term function of OPCs. Here in our study, we have successfully developed a novel pharmacogenetic model of conditional OPC ablation, eliminating 98.6% of all OPCs throughout the mouse brain for up to 12 days post ablation. In the future, we plan to combine the mouse model of complete OPC ablation with orthotopic glioma models to reveal the longitudinal and spatial functional roles and the necessity for resident OPCs in the tumor context. Understanding the OPC-tumor cell crosstalk by using our state-of-the-art approach at both cellular and molecular levels will have significant clinical implications for improving treatment for patients with pediatric gliomas.

A T Cell-Engaging Tumor Organoid Platform for Pancreatic Cancer Immunotherapy.

Pancreatic ductal adenocarcinoma (PDA) is a clinically challenging disease with limited treatment options. Despite a small percentage of cases with defective mismatch DNA repair (dMMR), PDA is included in the most immune-resistant cancer types that are poorly responsive to immune checkpoint blockade (ICB) therapy. To facilitate drug discovery combating this immunosuppressive tumor type, a high-throughput drug screen platform is established with the newly developed T cell-incorporated pancreatic tumor organoid model. Tumor-specific T cells are included in the pancreatic tumor organoids by two-step cell packaging, fully recapitulating immune infiltration in the immunosuppressive tumor microenvironment (TME). The organoids are generated with key components in the original tumor, including epithelial, vascular endothelial, fibroblast and macrophage cells, and then packaged with T cells into their outside layer mimicking a physical barrier and enabling T cell infiltration and cytotoxicity studies. In the PDA organoid-based screen, epigenetic inhibitors ITF2357 and I-BET151 are identified, which in combination with anti-PD-1 based therapy show considerably greater anti-tumor effect. The combinatorial treatment turns the TME from immunosuppressive to immunoactive, up-regulates the MHC-I antigen processing and presentation, and enhances the effector T cell activity. The standardized PDA organoid model has shown great promise to accelerate drug discovery for the immunosuppressive cancer.

Cholesterol efflux pathways hinder KRAS-driven lung tumor progenitor cell expansion

Cholesterol efflux pathways could be exploited in tumor biology to unravel cancer vulnerabilities. A mouse model of lung-tumor-bearing KRASG12D mutation with specific disruption of cholesterol efflux pathways in epithelial progenitor cells promoted tumor growth. Defective cholesterol efflux in epithelial progenitor cells governed their transcriptional landscape to support their expansion and create a pro-tolerogenic tumor microenvironment (TME). Overexpression of the apolipoprotein A-I, to raise HDL levels, protected these mice from tumor development and dire pathologic consequences. Mechanistically, HDL blunted a positive feedback loop between growth factor signaling pathways and cholesterol efflux pathways that cancer cells hijack to expand. Cholesterol removal therapy with cyclodextrin reduced tumor burden in progressing tumor by suppressing the proliferation and expansion of epithelial progenitor cells of tumor origin. Local and systemic perturbations of cholesterol efflux pathways were confirmed in human lung adenocarcinoma (LUAD). Our results position cholesterol removal therapy as a putative metabolic target in lung cancer progenitor cells.

A deep learning system to predict origins for cancers of unknown primary using cytological images from hydrothorax and ascites.

e13628 Background: Cancer of unknown primary (CUP) origin is still a mystery in the field of tumor diagnosis, which is difficult to be diagnosed by conventional imaging methods. The aim of this study is to develop a deep learning based method to assist pathologists in determining the origin of malignant hydrothorax and ascites using cytological images. Methods: By curating cytology images of hydrothorax and ascites from 42682 cases at three hospitals, we developed a deep-learning-based method -Tumor Origin diffeRentiation for Cytological Histology (TORCH)- for diagnosis of malignancy and prediction of tumor origin. We examined its performance on three individual test sets (n=12799). We compared TORCH with a panel of four pathologists on 496 cases that were randomly selected from test sets. Area under the receiver operating characteristic curve (AUROC) was used as the primary classification metric. Metrics including accuracy, sensitivity, specificity, precision and negative predictive value were used to measure the efficacy of TORCH versus pathologists. A score system was used to evaluate and compare the performance between our AI model and pathologist experts. Attention heatmap was used to interpret model prediction results. Results: TORCH model reached an overall micro-average one versus rest auroc of 0.957(95% CI: 0.955-0.959). On the three test sets, TORCH achieved an AUROC of 0.964 (95% CI 0.957-0.972), 0.947 (0.940-0.953), and 0.988 (0.985-0.993) in the diagnosis of cancer and 0.947 (0.942-0.952), 0.957 (0.953-0.960) and 0.972 (0.968-0.976) in localization of tumor origin, respectively. For primary tumor origin prediction, TORCH achieved an overall top-1 accuracy of 79.2% and top-3 accuracy of 98.5%. On three test sets, the top-1 accuracy was 75.7%, 79.4%, and 85.0% respectively. Compared with pathologists, TORCH demonstrated a better prediction efficacy (1.665 ± 0.677 vs. 1.265 ± 0.555; P <0.001). The mean diagnostic score of junior pathologists assisted with TORCH was also remarkably higher than the previous one (1.326 ± 0.728 vs. 1.101 ± 0.824; P <0.001). The comprehensive accuracy of attention heatmaps capturing main area of isolated tumor cells was 87.3% (95% CI: 81.9-92.8%). Conclusions: TORCH model was able to provide relatively accurate diagnosis of malignancy and prediction of tumor cell origin in hydrothorax and ascites. It can be used as an effective ancillary method to aid clinicians in allocating personalized therapy and improving patients’ prognosis.

YAP/BRD4-controlled ROR1 promotes tumor-initiating cells and hyperproliferation in pancreatic cancer.

Tumor-initiating cells are major drivers of chemoresistance and attractive targets for cancer therapy, however, their identity in human pancreatic ductal adenocarcinoma (PDAC) and the key molecules underlying their traits remain poorly understood. Here, we show that a cellular subpopulation with partial epithelial-mesenchymal transition (EMT)-like signature marked by high expression of receptor tyrosine kinase-like orphan receptor 1 (ROR1) is the origin of heterogeneous tumor cells in PDAC. We demonstrate that ROR1 depletion suppresses tumor growth, recurrence after chemotherapy, and metastasis. Mechanistically, ROR1 induces the expression of Aurora kinase B (AURKB) by activating E2F through c-Myc to enhance PDAC proliferation. Furthermore, epigenomic analyses reveal that ROR1 is transcriptionally dependent on YAP/BRD4 binding at the enhancer region, and targeting this pathway reduces ROR1 expression and prevents PDAC growth. Collectively, our findings reveal a critical role for ROR1high cells as tumor-initiating cells and the functional importance of ROR1 in PDAC progression, thereby highlighting its therapeutic targetability.

Abstract 3569: An animal model of GLI2-amplified medulloblastoma

Abstract Medulloblastoma (MB) is the most common malignant brain tumor affecting children. Among the known subtypes of MB, GLI2-amplified SHH-MB associated with P53 mutations has the worst prognosis, and a 5-year survival rate of less than 30%. Moreover, GLI2-amplified MBs are non-responsive to SMO inhibitors, the only targeted treatment option available for SHH-MB. To address this treatment gap, there is an urgent need to identify novel potential therapeutic targets, an effort that requires better understanding of key cellular and molecular mechanisms underlying GLI2-amplified MB. To that end, we generated a mouse model of GLI2-amplified MB and identified GL12 as the critical driver of tumorigenesis, and granule cell progenitors (GCPs) as the cells of tumor origin. We further found that GLI2 specifically drives embryonic, but not neonatal, Math1+ GCPs to form SHH-MB tumors. An scRNA-seq analysis revealed MAPK pathway activation specifically in embryonic Math1+ GCPs. The MAPK pathway was activated in mouse and human GLI2-driven MB tumors, and a MEK/ERK inhibitor significantly inhibited GLI2-driven MB in vivo. Based on these findings, we hypothesize that GLI2-driven MB originates from a specific population of Math1+ GCPs during a discrete temporal interval in cerebellar development, and that targeting MAPK/MEK/ERK pathway components represents a novel approach to treatment of GLI2-amplified MB. Citation Format: Yanxin Pei. An animal model of GLI2-amplified medulloblastoma. [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 3569.

Abstract 56: Unlocking primary cell culture for more relevant in vitro models

Abstract Tumor cell lines are commonly used to investigate biological and translational questions. However, many cell lines have been cultured in serum-containing medium for decades, continuously accumulating genetic and epigenetic aberrations. Without a doubt, these cell lines have very little in common with the tumor they originate from, resulting in low biological and clinical relevance. Despite these drawbacks, cell lines are still the most frequent research tool when it comes to the use of ex vivo models. Yet, in light of higher consistency, reproducibility, and biological relevance, more and more researchers are paying attention to which cells and culture medium to use. Although primary cell cultures certainly reflect cellular and genetic heterogeneity of the original tumor, finding a suitable medium that supports their growth and maintains genetic heterogeneity remains challenging. To this end, we developed serum-free cell culture media to cultivate primary epithelial tumor cells of pancreatic, renal, and ovarian origin. Notably, generating in vitro models with high biological relevance was successful when using our media during the derivation and expansion of tumor cell lines from primary and xenotransplanted tumors. Here, we present another serum-free cell culture media supporting the in vitro growth of primary colon adenocarcinoma. Using this optimized medium, we had a 42% success rate in establishing a primary cell culture for a given tumor sample, higher than for any other media tested in our hands. Next to 2D cell culture, our formulation supports 3D tumoroid formation when cells are embedded in a basement membrane matrix. Furthermore, targeted sequencing of 486 tumor-associated genes revealed that more than 99% of the detected genetic variants in an early passage (p11) were also present after extended time in culture (p53). In summary, our new serum-free medium enables the efficient derivation and expansion of primary tumor and xenograft-derived colon adenocarcinoma cell cultures in 2D and 3D, yet retaining their genetic identity. Citation Format: Benjamin Theek, Anne Franke, David Agorku, Katharina Lamfried, Nojan Jelveh, Michael Linnebacher, Lilian Martinez Carrera, Olaf Hardt. Unlocking primary cell culture for more relevant in vitro models [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 56.

Abstract 6551: HiTAIC: Hierarchical tumor artificial intelligence classifier traces tissue of origin and tumor type in primary and metastasized tumors using DNA methylation data

Abstract Background: Human cancers are heterogenous by their cell composition and origination site. Cancer metastasis generates the conundrum of the unknown origin of migrated tumor cells. Tracing tissue of origin and tumor type in primary and metastasized cancer is vital for clinical significance. Researchers have demonstrated the high performance of DNA methylation-based machine learning models tracing the tissue origin of tumor cells. However, previous models were devised based on tissue site instead of tumor type, generating potential problems of indistinguishable tumor subtypes from the same site, e.g., esophageal squamous cell carcinoma versus esophageal adenocarcinoma. Methods: we employed a novel tumor-type-specific hierarchical model using DNA methylation data to develop a multilayer perceptron model (MLP) to trace tumor tissue of origin and subtype. DNA methylation data on 7735 tumor samples from 27 cancer types were downloaded from GEO and TCGA to develop tumor-type-specific libraries. The discovery data set was split into 80% training and 20 % testing. The tumor classifier hierarchy was established with two layers for 27 cancer types. In each layer of the hierarchy, the MLP model was trained using the selected cancer-type discriminatory CpGs. HiTAIC was established based on the four hierarchical MLP models. To validate HiTAIC, we applied the model to the external validation data sets computing stratified and overall precision, recall, and f1-score to evaluate the performance. Next, we applied the model to the application data sets and used stratified and overall precision, recall, and f1-score to evaluate model performance in metastasized cancers. Results: We observed high accuracy of HiTAIC's performance in primary cancer tracing with 99% accuracy and 99% weighted average F1-score in the testing dataset. We observed 93% accuracy and 93% weighted average F1-score for external validation across 25 cancer types. In metastasized cancer, HiTAIC demonstrated 96% accuracy and 98% weighted average F1-score across five cancer types with six different metastatic locations. HiTAIC traces tumor tissue of origin and cancer subtype with high accuracy in primary and metastasized cancer. Conclusion: We developed HiTAIC, a DNA methylation-based classifier, to trace tissue of origin and tumor type in primary and metastasized tumors. The model's capability to trace the tumor origin and subtype with high resolution and accuracy promises potential clinical use in identifying cancer of unknown origin. HiTAIC can be easily deployed in a web-based application, transforming computational sophistication into a user-friendly public tool. Citation Format: Ze Zhang, Brock Christensen, Lucas Salas. HiTAIC: Hierarchical tumor artificial intelligence classifier traces tissue of origin and tumor type in primary and metastasized tumors using DNA methylation data. [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 6551.

Accumulation of STR-Loci Aberrations in Subclones of Jurkat Cell Line as a Model of Tumor Clonal Evolution

Many genetic markers are known to distinguish tumor cells from normal. Genetic lesions found at disease onset often belong to a predominant tumor clone, and further observation makes it possible to assess the fate of this clone during therapy. However, minor clones escape monitoring and become unidentified, leading to relapses. Here we report the results of in vitro study of clonal evolution in cultured tumor cell line (Jurkat) compared to the cell line of non-tumor origin (WIL2-S). Cell lines were cultured and cloned by limiting dilutions. Subclones were tested by short tandem repeats (STR) profiling. Spontaneous STR aberrations in cells of non-tumor origin occur in less than 1 of 100 cultured cells. While in the cells of tumor origin, new aberrations appear in 1 or even more of 3 cultured cells. At the same time, a significant relationship was found between the accumulation of aberrations in the pool of subclones and the rate of cell growth. One can speculate that this approach could be applied for the analysis of primary patient tumor cell culture to obtain information concerning the evolutionary potential of the tumor cells that may be useful for the selection of a therapy approach.

The gut microbiota correlate with the disease characteristics and immune status of patients with untreated diffuse large B-cell lymphoma.

Gut microbiota characteristics in patients with diffuse large B-cell lymphoma (DLBCL) are reportedly different when compared with the healthy population and it remains unclear if the gut microbiota affects host immunity and clinical disease features. This research investigated the gut microbiota in patients with untreated DLBCL and analyzed its correlation with patient clinical characteristics, humoral, and cell immune status. Thirty-five patients with untreated DLBCL and 20 healthy controls (HCs) were recruited to this study and microbiota differences in stool samples were analyzed by 16S rDNA sequencing. Absolute ratios of immune cell subset counts in peripheral blood were detected by flow cytometry and peripheral blood cytokine levels were detected by enzyme-linked immunosorbent assay. Relationships between changes in patient microbiomes and clinical characteristics, such as clinical stage, international prognostic index (IPI) risk stratification, cell origin, organ involved and treatment responses were investigated and correlations between differential microbiota and host immune indices were analyzed. The alpha-diversity index of intestinal microecology in DLBCL patients was not significantly different when compared with HCs (P>0.05), nonetheless beta-diversity was significantly decreased (P=0.001). p_Proteobacteria were dominant in DLBCL, while p_Bacteroidetes abundance was significantly decreased when compared with HCs (P<0.05). Gut microbiota characteristics were identified that were associated with clinical features, such as tumor load, risk stratification and cell origin, and correlation analyses were performed between differential flora abundance associated with these clinical features and host immune status. The p_Firmicutes was positively correlated with absolute lymphocyte values, g_Prevotella_2 and s_un_g_Prevotella_2 were negatively correlated with absolute lymphocyte values, T cell counts and CD4 cell counts, while g_Pyramidobacter, s_un_g_Pyramidobacter, and f_Peptostreptococcaceae were negatively correlated with IgA. Dominant gut microbiota, abundance, diversity, and structure in DLBCL were influenced by the disease, correlated with patient immune status and this suggested that the microecology-immune axis may be involved in regulating lymphoma development. In the future, it may be possible to improve immune function in patients with DLBCL by regulating the gut microbiota, improve treatment response rates and increase patient survival rates.

Rank ectopic expression in the presence of Neu and PyMT oncogenes alters mammary epithelial cell populations and their tumorigenic potential

Determination of the mammary epithelial cell that serves as the cell of origin for breast cancer is key to understand tumor heterogeneity and clinical management. In this study, we aimed to decipher whether Rank expression in the presence of PyMT and Neu oncogenes might affect the cell of origin of mammary gland tumors. We observed that Rank expression in PyMT+/− and Neu+/− mammary glands alters the basal and luminal mammary cell populations already in preneoplasic tissue, which may interfere with the tumor cell of origin restricting their tumorigenesis ability upon transplantation assays. In spite of this, Rank expression eventually promotes tumor aggressiveness once tumorigenesis is established.

Usefulness and Limitations of Cryopreservation for Immunocytochemical Staining of Canine Cytological Specimens for Detection of Cytokeratin and Vimentin.

Immunocytochemistry is an advanced diagnostic tool for identifying the origin of tumor cells. This study aimed to highlight the usefulness of cryopreserved, air-dried cytological samples in detecting cytokeratin and vimentin. Air-dried cytological smear samples were prepared from a total of 39 resected canine tumors and stored in a medical freezer without fixation. The duration of cryopreservation ranged from 2 to 56 months. The same tumors were processed for routine histopathological examination. Based on the morphological diagnosis, cryopreserved FNA smears from epithelial tumors were stained by enzymatic immunocytochemistry (ICC) for cytokeratin; those from mesenchymal and melanocytic tumors were stained by ICC for vimentin. To ascertain the positivity of tumor cells to the selected markers, tissue paraffin-embedded sections were also stained by immunohistochemistry (IHC) for the same markers. Immunoreactivity for cytokeratin was detected in cryopreserved cytological smears for a maximum of 46 months. Immunoreactivity for vimentin was clearly detected for 33 months. Smears stored at room temperature for 1 week did not show any signals under immunocytochemical examination. Thus, immunocytochemistry for cytokeratin and vimentin can be safely applied to air-dried smears cryopreserved in a freezer for at least 33 months.

Tumor-targeted suicide gene-directed enzyme prodrug therapy mediated by extracellular vesicles.

In this article, we describe the gene-directed enzyme prodrug therapy, also known as the "Trojan Horse" therapy mediated by exosomes - small extracellular vesicles (sEVs) secreted from mesenchymal stem/stromal cells (MSCs) and cancer cells. MSC-EVs possess strong migrating tropism toward tumor sites. EVs derived from tumor cells mimic the parental cells in an invasive metastatic growth trait and the capability to reprogram the recipient cells. The behavior of these EVs when modified with the suicide gene predestinates them to be a drug with guided intracellular action. EVs with therapeutic suicide gene are prepared from cells with integrated retrovirus vector containing its genetic message. These EVs are internalized by tumor cells and the product of the gene converts the non-toxic prodrug into a cytotoxic drug inside the cell causing its suicide. The action of two suicide gene systems are described: the yCD::UPRT-MSC/5-FC system and the HSVTK-MSC-GCV system. Suicide gene EVs either MSCs or tumor cell origin due to their intrinsic targeting capabilities, high modification flexibility, as well as biological barrier permeability represent potential drugs for tumors untreatable with present standard cancer therapies.

Do the two components have a common origin in coexisting tumor of craniopharyngioma and pituitary adenoma?

The coexistence of craniopharyngioma and pituitary adenoma in sellar region increased gradually in recent years. The origin for the two types of tumor cells has become controversial. We have reviewed the recent literatures and proposed a hypothesis: The origin of tumor cells is related to the type of craniopharyngioma in the coexisting tumors of craniopharyngioma and pituitary adenoma. The two tumor cells originate from different precursor cells if craniopharyngioma is papillary craniopharyngioma and the same kind of precursor cell if craniopharyngioma is adamantinomatous craniopharyngioma, which is derived from the proliferation of pituitary progenitor/stem cells induced by the accumulation of oncogenic β-catenin. This hypothesis is helpful to complete the coexisting process of craniopharyngioma and pituitary adenoma. Meanwhile, it is of great significance to reveal the causes of coexisting tumor in sellar region.

Attenuated WNV-poly(A) exerts a broad-spectrum oncolytic effect by selective virus replication and CD8+ T cell-dependent immune response

As an emerging tumor therapy, ideal oncolytic viruses preferentially replicate in malignant cells, reverse the immunosuppressive tumor microenvironment, and eventually can be eliminated by the patient. It is of great significance for cancer treatment to discover new excellent oncolytic viruses. Here, we found that WNV live attenuated vaccine WNV-poly(A) could be developed as a novel ideal oncolytic agent against several types of cancers. Mechanistically, due to its high sensitivity to type Ι interferon (IFN-Ι), WNV-poly(A) could specifically kill tumor cells rather than normal cells. At the same time, WNV-poly(A) could activate Dendritic cells (DCs) and trigger tumor antigen specific response mediated by CD8 + T cell, which contributed to inhibit the propagation of original and distal tumor cells. Like intratumoral injection, intravenous injection with WNV-poly(A) also markedly delays Huh7 hepatic carcinoma (HCC) transplanted tumor progression. Most importantly, in addition to an array of mouse xenograft tumor models, WNV-poly(A) also has a significant inhibitory effect on many different types of patient-derived tumor tissues and HCC patient-derived xenograft (PDX) tumor models. Our studies reveal that WNV-poly(A) is a potent and excellent oncolytic agent against many types of tumors and may have a role in metastatic and recurrent tumors.