Abstract Breast cancer is a leading cause of cancer-related mortality for women worldwide. Hormone receptor-positive (HR+) breast tumors, which represent 70% of all breast cancer cases, are treated with endocrine therapy. However, not all patients benefit from this treatment regimen because of patient-to-patient variation. Therefore, high throughput drug screening system is warranted to enable personalized medicine. Patient-derived organoids, which serve as a screening platform, lose their hormone receptors and response upon ex vivo culturing, and may not be adequate models for HR+ breast tumors. Moreover, unidentified biological components in the widely-used basement membrane matrix, Matrigel, result in high batch-to-batch variations and poor reproducibility in organoid cultures. Here, we propose a hydrogel-based 3D ex vivo model with defined structural and chemical properties to test hormone and drug sensitivity of HR+ breast tumors from patient-derived xenografts (PDXs) and patient tumor biopsies using microfluidics. Our data demonstrate the feasibility of this model to preserve cell proliferation and hormone receptor expression over 7 days. We also demonstrate that responses to hormones and FDA-approved drugs are faithfully maintained in this model. Finally, to establish a high throughput hormone and drug testing workflow with transcriptomic readout, we multiplexed barcoded- and drug-treated tumor samples in a single experiment with bulk RNA-sequencing. Our preliminary data demonstrate patient-specific responses to hormones and drugs that correspond to patient genetic mutation profiles, treatment history, disease stages and subtypes. This platform also enables testing of drugs in clinical trials that shows promising therapeutic outcomes for breast cancer, such as CDK4/6i, AKTi, PARPi, mTORi and their combination with endocrine therapy, thanks to the high throughput of the screening system and the low consumption of patient-derived or patient tissue. Given the capability of combining this physiologically-relevant 3D ex vivo model with RNA-seq for HR+ breast tumors, this platform holds potential for high throughput compound testing and transcriptomic profiling of patient biopsies for personalized medicine. Citation Format: Yueyun Zhang, Carlos Henrique Venturi Ronchi, Giovanna Ambrosini, Yuanlong Liu, Patrick Aouad, Daria Matvienko, Christoph Merten, Cathrin Brisken. Transcriptomics-based drug screening in 3D ex vivo patient-derived breast cancer model and patient biopsy for personalized therapy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-14-06.
More than two-thirds of cancer-related deaths are attributable to metastases. In some tumor types metastasis can occur up to 20 years after diagnosis and successful treatment of the primary tumor, a phenomenon termed late recurrence. Metastases arise from disseminated tumor cells (DTCs) that leave the primary tumor early on in tumor development, either as single cells or clusters, adapt to new environments, and reduce or shut down their proliferation entering a state of dormancy for prolonged periods of time. Dormancy has been difficult to track clinically and study experimentally. Recent advances in technology and disease modeling have provided new insights into the molecular mechanisms orchestrating dormancy and the switch to a proliferative state. A new role for epithelial-mesenchymal transition (EMT) in inducing plasticity and maintaining a dormant state in several cancer models has been revealed. In this review, we summarize the major findings linking EMT to dormancy control and highlight the importance of pre-clinical models and tumor/tissue context when designing studies. Understanding of the cellular and molecular mechanisms controlling dormant DTCs is pivotal in developing new therapeutic agents that prevent distant recurrence by maintaining a dormant state.
Supplementary Figure S1. Effect of ST1926 on the viability of AML cells; Supplementary Figure S2. Effect of ST1926 on the viability of normal human stem cells; Supplementary Figure S3. Representative histogram analysis of the effects of ST1926 on the cell cycle distribution of AML cells; Supplementary Table 1: Peritoneal volumes (cm3) of treated (n=5 for each group) versus control mice (n=5 for each group) determined at 24-days post-treatment
Retinoblastoma is the most common pediatric eye cancer. It is currently treated with a limited number of drugs, adapted from other pediatric cancer treatments. Drug toxicity and relapse of the disease warrant new therapeutic strategies for these young patients. In this study, we developed a robust tumoroid‐based platform to test chemotherapeutic agents in combination with focal therapy (thermotherapy) – a treatment option widely used in clinical practice – in accordance with clinically relevant trial protocols. The model consists of matrix‐embedded tumoroids that retain retinoblastoma features and respond to repeated chemotherapeutic drug exposure similarly to advanced clinical cases. Moreover, the screening platform includes a diode laser (810 nm, 0.3 W) to selectively heat the tumoroids, combined with an on‐line system to monitor the intratumoral and surrounding temperatures. This allows the reproduction of the clinical settings of thermotherapy and combined chemothermotherapy treatments. When testing the two main drugs currently used in clinics to treat retinoblastoma in our model, we observed results similar to those clinically obtained, validating the utility of the model. This screening platform is the first system to accurately reproduce clinically relevant treatment methods and should lead to the identification of more efficient drugs to treat retinoblastoma.
Fate decisions in the embryo are controlled by a plethora of microenvironmental interactions in a three-dimensional niche. To investigate whether aspects of this microenvironmental complexity can be engineered to direct myogenic human-induced pluripotent stem cell (hiPSC) differentiation, we here screened murine cell types present in the developmental or adult stem cell niche in heterotypic suspension embryoids. We identified embryonic endothelial cells and fibroblasts as highly permissive for myogenic specification of hiPSCs. After two weeks of sequential Wnt and FGF pathway induction, these three-component embryoids are enriched in Pax7-positive embryonic-like myogenic progenitors that can be isolated by flow cytometry. Myogenic differentiation of hiPSCs in heterotypic embryoids relies on a specialized structural microenvironment and depends on MAPK, PI3K/AKT, and Notch signaling. After transplantation in a mouse model of Duchenne muscular dystrophy, embryonic-like myogenic progenitors repopulate the stem cell niche, reactivate after repeated injury, and, compared to adult human myoblasts, display enhanced fusion and lead to increased muscle function. Altogether, we provide a two-week protocol for efficient and scalable suspension-based 3D derivation of Pax7-positive myogenic progenitors from hiPSCs.
More than 70% of human breast cancers (BCs) are estrogen receptor α-positive (ER + ). A clinical challenge of ER + BC is that they can recur decades after initial treatments. Mechanisms governing latent disease remain elusive due to lack of adequate in vivo models. We compare intraductal xenografts of ER + and triple-negative (TN) BC cells and demonstrate that disseminated TNBC cells proliferate similarly as TNBC cells at the primary site whereas disseminated ER + BC cells proliferate slower, they decrease CDH1 and increase ZEB1 , 2 expressions, and exhibit characteristics of epithelial-mesenchymal plasticity (EMP) and dormancy. Forced E-cadherin expression overcomes ER + BC dormancy. Cytokine signalings are enriched in more active versus inactive disseminated tumour cells, suggesting microenvironmental triggers for awakening. We conclude that intraductal xenografts model ER + BC dormancy and reveal that EMP is essential for the generation of a dormant cell state and that targeting exit from EMP has therapeutic potential.
Invasive lobular carcinoma (ILC) is the most frequent special histological subtype of breast cancer, typically characterized by loss of E-cadherin. It has clinical features distinct from other estrogen receptor-positive (ER+ ) breast cancers but the molecular mechanisms underlying its characteristic biology are poorly understood because we lack experimental models to study them. Here, we recapitulate the human disease, including its metastatic pattern, by grafting ILC-derived breast cancer cell lines, SUM-44 PE and MDA-MB-134-VI cells, into the mouse milk ducts. Using patient-derived intraductal xenografts from lobular and non-lobular ER+ HER2- tumors to compare global gene expression, we identify extracellular matrix modulation as a lobular carcinoma cell-intrinsic trait. Analysis of TCGA patient datasets shows matrisome signature is enriched in lobular carcinomas with overexpression of elastin, collagens, and the collagen modifying enzyme LOXL1. Treatment with the pan LOX inhibitor BAPN and silencing of LOXL1 expression decrease tumor growth, invasion, and metastasis by disrupting ECM structure resulting in decreased ER signaling. We conclude that LOXL1 inhibition is a promising therapeutic strategy for ILC.
Estrogen receptor α-positive (ER+) breast cancers (BCs) represent more than 70% of all breast cancers and pose a particular clinical challenge because they recur up to decades after initial diagnosis and treatment. The mechanisms governing tumor cell dormancy and latent disease remain elusive due to a lack of adequate models. Here, we compare tumor progression of ER+ and triple-negative (TN) BC subtypes with a clinically relevant mouse intraductal xenografting approach (MIND). Both ER+ and TN BC cells disseminate already during the in situ stage. However, TN disseminated tumor cells (DTCs) proliferate at the same rate as cells at the primary site and give rise to macro-metastases. ER+ DTCs have low proliferative indices, form only micro-metastases and lose epithelial characteristics. Expression of CDH1 is decreased whereas the mesenchymal marker VIM and the transcription factors, ZEB1 / ZEB2, which control epithelial-mesenchymal plasticity (EMP) are increased. EMP is not detected earlier during ER+ BC development and not required for invasion or metastasis. In vivo , forced transition to the epithelial state through ectopic E-cadherin expression overcomes dormancy with increased growth of lung metastases. We conclude that EMP is essential for the generation of a dormant cell state and the development of latent disease. Targeting exit from EMP is of therapeutic potential.
Abstract Colorectal cancer is the third most common neoplasia and the second cause of cancer-related deaths worldwide. Unlike normal cells, tumor cells reprogram metabolic pathways to meet their bioenergetics, redox, biosynthetic demands and rely mostly on aerobic glycolysis (Warburg effect). Colorectal cancer cells upregulate the pentose phosphate pathway (PPP), and p53 is a crucial regulator. The PPP is a significant route for glucose catabolism and is required for DNA synthesis of rapidly-proliferating cells. Its oxidative phase (oxPPP), catalyzed by the rate-limiting enzyme glucose-6-phosphate dehydrogenase (G6PD), provides the cell with nicotinamide adenine dinucleotide phosphate (NADPH) that is needed for biosynthetic and detoxifying processes. For the past six decades, 5-Fluorouracil (5-FU) has been the treatment of choice in colorectal cancer. However, 5-FU exhibits high toxicity and drug resistance in patients. Therefore, we hypothesized that targeting the PPP might offer novel therapeutic opportunities in colorectal cancer and improve the response to 5-FU at lower and safer doses. Accordingly, we aim to investigate and characterize the anti-tumor effect of the G6PD inhibitor, 6-aminonicotinamide (6-AN), alone, or in combination with 5-FU on colorectal cancer cells. We explored the effects of oxPPP inhibition on colorectal cancer cell growth, reactive oxygen species (ROS) production, cell cycle regulation, and senescence. We have shown that 6-AN arrested cell growth in HCT116 and HCT116 p53−/− colorectal cancer cells while spared normal-like colon cells (NCM460D). Moreover, 6-AN induced S-phase arrest and early senescence in HCT116 cells as demonstrated by cell cycle analysis using flow cytometry and senescence-associated beta-galactosidase assay, respectively. We also tested the effects of 6-AN/5-FU combination treatments on cellular viability using MTT assay and validated our results using SRB and trypan blue exclusion assays. Interestingly, combination treatments of 6-AN with 5-FU resulted in synergistic effects as estimated using Compusyn software. We used HCT116 colorectal cancer cells resistant to 5-FU (HCT116 5FU-R) or lacking p53, as models for tumor resistance. Importantly, the combination treatment sensitized both HCT116 p53−/− and HCT116 5FU-R colorectal cancer cells to 5-FU and was accompanied by a reduction in G6PD activity and increased ROS using NBT reduction assay. Our findings indicate that combining 6-AN with 5-FU may decrease resistance and further sensitize colorectal cancer cells to 5-FU treatment independently of p53 and drug resistance status. Exploiting this metabolic vulnerability may offer a novel clinical approach and improve patient's therapy. Citation Format: Noorhan Ghanem, Chirine El Baba, Lara Al Saleh, Berthe Hayar, Patrick Aouad, Marwa Al Hassan, Riyad El-Khoury, Julnar Usta, Nadine Darwiche. Therapeutic targeting of the pentose phosphate pathway in colorectal cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 236.
Estrogens and progesterone control breast development and carcinogenesis via their cognate receptors expressed in a subset of luminal cells in the mammary epithelium. How they control the extracellular matrix, important to breast physiology and tumorigenesis, remains unclear. Here we report that both hormones induce the secreted protease Adamts18 in myoepithelial cells by controlling Wnt4 expression with consequent paracrine canonical Wnt signaling activation. Adamts18 is required for stem cell activation, has multiple binding partners in the basement membrane and interacts genetically with the basal membrane-specific proteoglycan, Col18a1, pointing to the basement membrane as part of the stem cell niche. In vitro, ADAMTS18 cleaves fibronectin; in vivo, Adamts18 deletion causes increased collagen deposition during puberty, which results in impaired Hippo signaling and reduced Fgfr2 expression both of which control stem cell function. Thus, Adamts18 links luminal hormone receptor signaling to basement membrane remodeling and stem cell activation.
Colorectal cancer (CRC) remains a leading cause of cancer-related morbidity and mortality worldwide. Although targeted therapy in combination with chemotherapy in CRC prolongs the overall survival of patients with metastatic disease, acquired resistance and relapse hinder their clinical benefits. Moreover, patients with some specific genetic profile are unlikely to benefit from targeted therapy, suggesting the need for safe and effective treatment strategies. Retinoids, comprising of natural and synthetic analogs, are a class of chemical compounds that regulate cellular proliferation, differentiation, and cell death. Retinoids have been used in the clinic for several leukemias and solid tumors, either as single agents or in combination therapy. Furthermore, retinoids have shown potent chemotherapeutic and chemopreventive properties in different cancer models, including CRC. In this review, we summarize the major preclinical findings in CRC in which natural and synthetic retinoids showed promising antitumor activities and stress on the proposed mechanisms of action. Understanding of the retinoids' antitumor mechanisms would provide insights to support and warrant their development in the management of CRC.
Estrogen receptor α positive (ER+) or “luminal” breast cancers were notoriously difficult to establish as patient-derived xenografts (PDXs). We and others recently demonstrated that the microenvironment is critical for ER+ tumor cells; by grafting them into milk ducts >90% take rates are achieved and many features of the human disease are recapitulated. This intra-ductal (ID) approach holds promise for personalized medicine, yet human and murine stroma are organized differently and this and other species specificities may limit the value of this model. Here, we analyzed 21 ER+ ID-PDXs histopathologically. We find that ID-PDXs vary in extent and define four histopathological patterns: flat, lobular, in situ , and invasive, which occur in pure and combined forms. The ID-PDXs replicate earlier stages of tumor development than their clinical counterparts. Micrometastases are already detected when lesions appear in situ . Tumor extent, histopathological patterns, and metastatic load correlate with biological properties of their tumors of origin. Our findings add evidence to the validity of the intraductal model for in vivo studies of ER+ breast cancer and raise the intriguing possibility that tumor cell dissemination may occur earlier than currently thought. Conflict of interest statement: The authors declare no conflict of interest.
Oestrogen receptor α (ERα) is a transcription factor with ligand-independent and ligand-dependent activation functions (AF)-1 and -2. Oestrogens control postnatal mammary gland development acting on a subset of mammary epithelial cells (MECs), termed sensor cells, which are ERα-positive by immunohistochemistry (IHC) and secrete paracrine factors, which stimulate ERα-negative responder cells. Here we show that deletion of AF-1 or AF-2 blocks pubertal ductal growth and subsequent development because both are required for expression of essential paracrine mediators. Thirty percent of the luminal cells are ERα-negative by IHC but express Esr1 transcripts. This low level ERα expression through AF-2 is essential for cell expansion during puberty and growth-inhibitory during pregnancy. Cell-intrinsic ERα is not required for cell proliferation nor for secretory differentiation but controls transcript levels of cell motility and cell adhesion genes and a stem cell and epithelial mesenchymal transition (EMT) signature identifying ERα as a key regulator of mammary epithelial cell plasticity.
Despite advances in therapeutic strategies, colorectal cancer (CRC) remains the third cause of cancer-related deaths with a relatively low survival rate. Resistance to standard chemotherapy represents a major hurdle in disease management; therefore, developing new therapeutic agents demands a thorough understanding of their mechanisms of action. One of these compounds is ST1926, an adamantyl retinoid that has shown potent antitumor activities in several human cancer models. Here, we show that ST1926 selectively suppressed the proliferation of CRC cells while sparing normal counterparts, and significantly reduced tumor volume in a xenograft cancer mouse model. Next, we investigated the effects of ST1926 in CRC cells and observed early DNA damage, S-phase arrest, dissipation of mitochondrial membrane potential, and apoptosis induction, in a p53 and p21-independent manner. To address the underlying mechanism of resistance to ST1926, we generated ST1926-resistant HCT116 cells and sequenced DNA polymerase α (POLA1), which was reported to be a direct target to the drug's parent molecule, CD437. We identified similar mutations in POLA1 that conferred resistance to ST1926 and CD437. These mutations were absent in 5-fluorouracil-resistant HCT116 cells, clearly validating the specificity of these mutations to the lack of DNA damage and acquired resistance to ST1926. ST1926 also inhibited POLA1 activity and reduced its protein expression levels. Further, in silico analysis of normal and malignant tissue expression data demonstrated that POLA1 levels are elevated in CRC cells and tissues compared to normal counterparts as well as to other cancer types. Our findings highlight previously uncharacterized mechanisms of action of ST1926 in CRC and suggest that elevated POLA1 expression is a pertinent molecular feature and an attractive target in CRC.
Abstract Acute myeloid leukemia (AML) represents one of the most complex types of leukemia. It is a clinically and genetically heterogeneous disorder of hematopoietic progenitor cells, which have lost their ability to differentiate normally. Retinoids regulate vital biological processes including development, differentiation, proliferation, and cell death of hematopoietic progenitor cells. The natural retinoid all-trans retinoic acid (ATRA) became the paradigm for the treatment of acute promyelocytic leukemia (APL), an AML subtype. However, in non-APL AML patients, ATRA is possibly only effective in patients with Nucleophosmin-1 mutations without FMS-like tyrosine kinase 3 internal tandem duplication (FLT-3 ITD). Therefore, synthetic retinoids, specifically the adamantyl ST1926, emerged as potential alternatives. However, despite its lack of toxicity, ST1926 development in clinic was limited due to its rapid glucuroconjugation resulting in low plasma concentrations. Nanomedicine enables more efficient drug delivery and bioavailability. Here, we investigate the pre-clinical efficacy of ST1926 and polymer stabilized ST1926 nanoparticles in AML in vitro and in vivo models. We show that ST1926, at low sub-µM concentrations, potently inhibited the growth of human non-APL ATRA-resistant AML cell lines and AML patient cells while sparing resting and activated normal leukocytes at ten- to hundred-fold higher concentrations. ST1926 induced early DNA damage and massive apoptosis in all tested AML cell lines. To optimize the drug’s bioavailability burden, polymer stabilized ST1926 nanoparticles were developed using Flash NanoPrecipitation, and were shown to display comparable anti-growth activities to the naked drug in vitro. In murine AML xenograft model, ST1926 and ST1926 nanoparticles significantly prolonged survival. Strikingly, ST1926 encapsulated in nanoparticles extended survival in AML xenografted mice at four-fold lower concentrations than the naked drug. These results highlight the promise of ST1926 in AML therapy and warrant further clinical development of this adamantly retinoid. Citation Format: Leeanna El-Houjeiri, Walid Saad, Berthe Hayar, Patrick Aouad, Nadim Tawil, Rana Abdel-Samad, Claudio Pisano, Ali Bazarbachi, Hiba El Hajj, Nadine Darwiche. Encapsulation of the atypical retinoid ST1926 in nanoparticles prolongs the survival of acute myeloid leukemia xenografted mice at multiple folds lower concentrations than the naked drug [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5140. doi:10.1158/1538-7445.AM2017-5140
AbstractAcute myeloid leukemia (AML) is one of the most frequent types of blood malignancies. It is a complex disorder of undifferentiated hematopoietic progenitor cells. The majority of patients generally respond to intensive therapy. Nevertheless, relapse is the major cause of death in AML, warranting the need for novel treatment strategies. Retinoids have demonstrated potent differentiation and growth regulatory effects in normal, transformed, and hematopoietic progenitor cells. All-trans retinoic acid (ATRA) is the paradigm of treatment in acute promyelocytic leukemia, an AML subtype. The majority of AML subtypes are, however, resistant to ATRA. Multiple synthetic retinoids such as ST1926 recently emerged as potent anticancer agents to overcome such resistance. Despite its lack of toxicity, ST1926 clinical development was restricted due to its limited bioavailability and rapid excretion. Here, we investigate the preclinical efficacy of ST1926 and polymer-stabilized ST1926 nanoparticles (ST1926-NP) in AML models. We show that sub-μmol/L concentrations of ST1926 potently and selectively inhibited the growth of ATRA-resistant AML cell lines and primary blasts. ST1926 induced-growth arrest was due to early DNA damage and massive apoptosis in AML cells. To enhance the drug's bioavailability, ST1926-NP were developed using Flash NanoPrecipitation, and displayed comparable anti-growth activities to the naked drug in AML cells. In a murine AML xenograft model, ST1926 and ST1926-NP significantly prolonged survival and reduced tumor burden. Strikingly, in vivo ST1926-NP antitumor effects were achieved at four fold lower concentrations than the naked drug. These results highlight the promising use of ST1926 in AML therapy and encourage its further development. Mol Cancer Ther; 16(10); 2047–57. ©2017 AACR.
Despite recent advances in chemotherapy, aggressive and metastatic breast cancers remain refractory to targeted therapy and the development of novel drugs is urgently needed. Retinoids are crucial regulators of cellular proliferation, differentiation, and cell death, and have shown potent chemotherapeutic and chemopreventive properties. The major drawback of the use of all-trans retinoic acid (ATRA) in cancer therapy is disease relapse. Therefore, synthetic retinoids, specifically ST1926, have emerged as potent anticancer agents. Given the importance of the microenvironment in modulating the response of cancer cells to chemotherapeutic drugs, we investigated the antitumor activities of ST1926 in two-dimensional (2D) and different three-dimensional (3D) human breast cancer models and compared them with ATRA. We have shown that in 2D cell culture models, ATRA-resistant MCF-7 and MDA-MB-231 cells were sensitive to ST1926 at submicromolar concentrations that spared the 'normal-like' breast epithelial cells. ST1926 induced apoptosis and S-phase arrest, caused DNA damage, and downregulated the Wnt/β-catenin pathway in breast cancer cells in 2D and 3D cell culture models. ST1926-mediated growth inhibition was independent of the retinoid receptor-signaling pathway. Long-term treatments with low submicromolar ST1926 concentrations reduced the anchorage-independent growth and decreased the sphere-forming ability of breast cancer progenitor cells in the sphere formation assay. Furthermore, ST1926 potently induced cell death of breast cancer cells under 3D conditions and spared the lumen-forming ability of normal-like breast epithelial cells. In tested 3D models, ATRA had minimal effects on the growth of breast cancer cells compared with ST1926. In summary, our results highlight the therapeutic potential of ST1926 in breast cancer and warrant its further clinical development.
Years of research in the field of neurotrauma have led to the concept of applying systems biology as a tool for biomarker discovery in traumatic brain injury (TBI). Biomarkers may lead to understanding mechanisms of injury and recovery in TBI and can be potential targets for wound healing, recovery, and increased survival with enhanced quality of life. The literature available on neurotrauma studies from both animal and clinical studies has provided rich insight on the molecular pathways and complex networks of TBI, elucidating the proteomics of this disease for the discovery of biomarkers. With such a plethora of information available, the data from the studies require databases with tools to analyze and infer new patterns and associations. The role of different systems biology tools and their use in biomarker discovery in TBI are discussed in this chapter.
The application of systems biology tools in analyzing heterogeneous data from multiple sources has become a necessity, especially in biomarker discovery. Such tools were developed with several approaches to address different types of research questions and hypotheses. In the field of neurotrauma and traumatic brain injury (TBI), three distinct approaches have been used so far as systems biology tools, namely functional group categorization, pathway analysis, and protein-protein interaction (PPI) networks. The databases allow for query of the system to identify candidate targets which can be further studied to elucidate potential downstream biomarkers indicative of disease progression, severity, and improvement. The various systems biology tools, databases, and strategies that can be implemented on available TBI data in neuroproteomic studies are discussed in this chapter.