Radiosensitization effect of quinoline-indole-schiff base derivative 10E on non-small cell lung cancer cells in vitro and in tumor xenografts.

Radioresistance is an inevitable obstacle in the clinical treatment of inoperable patients with non-small cell lung cancer (NSCLC). Combining treatment with radiosensitizers may improve the efficacy of radiotherapy. Previously, the quinoline derivative 10E as new exporter of Nur77 has shown superior antitumor activity in hepatocellular carcinoma. Here, we aimed to investigate the radiosensitizing activity and acting mechanisms of 10E. In vitro, A549 and H460 cells were treated with control, ionizing radiation (IR), 10E, and 10E + IR. Cell viability, apoptosis, and cycle were examined using CCK-8 and flow cytometry assays. Protein expression and localization were examined using western blotting and immunofluorescence. Tumor xenograft models were established to evaluate the radiosensitizing effect of 10E in vivo. 10E significantly inhibited cell proliferation and increased their radiosensitivity while reducing level of p-BCRA1, p-DNA-PKs, and 53BP1 involved in the DNA damage repair pathway, indicating that its radiosensitizing activity is closely associated with repressing DNA damage repair. A549 cells showed low level of Nur77 and a low response to IR but 10E-treated A549 cells showed high level of Nur77 indicating that Nur77 is a core radiosensitivity factor and 10E restores the expression of Nur77. Nur77 and Ku80 extranuclear co-localization in the 10E-treated A549 cells suggested that 10E-modulated Nur77 nuclear exportation inhibits DNA damage repair pathways and increases IR-triggered apoptosis. The combination of 10E and IR significantly inhibits tumor growth in a tumor xenograft model. Our findings suggest that 10E acts as a radiosensitizer and that combining 10E with radiotherapy may be a potential strategy for NSCLC treatment.

The OVAREX study: Establishment of ex vivo ovarian cancer models to validate innovative therapies and to identify predictive biomarkers.

BACKGROUND: Ovarian cancer is the first cause of death from gynecological malignancies mainly due to development of chemoresistance. Despite the emergence of PARP inhibitors, which have revolutionized the therapeutic management of some of these ovarian cancers, the 5-year overall survival rate remains around 45%. Therefore, it is crucial to develop new therapeutic strategies, to identify predictive biomarkers and to predict the response to treatments. In this context, functional assays based on patient-derived tumor models could constitute helpful and relevant tools for identifying efficient therapies or to guide clinical decision making. METHOD: The OVAREX study is a single-center non-interventional study which aims at investigating the feasibility of establishing in vivo and ex vivo models and testing ex vivo models to predict clinical response of ovarian cancer patients. Patient-Derived Xenografts (PDX) will be established from tumor fragments engrafted subcutaneously into immunocompromised mice. Explants will be generated by slicing tumor tissues and Ascites-Derived Spheroids (ADS) will be isolated following filtration of ascites. Patient-derived tumor organoids (PDTO) will be established after dissociation of tumor tissues or ADS, cell embedding into extracellular matrix and culture in specific medium. Molecular and histological characterizations will be performed to compare tumor of origin and paired models. Response of ex vivo tumor-derived models to conventional chemotherapy and PARP inhibitors will be assessed and compared to results of companion diagnostic test and/or to the patient's response to evaluate their predictive value. DISCUSSION: This clinical study aims at generating PDX and ex vivo models (PDTO, ADS, and explants) from tumors or ascites of ovarian cancer patients who will undergo surgical procedure or paracentesis. We aim at demonstrating the predictive value of ex vivo models for their potential use in routine clinical practice as part of precision medicine, as well as establishing a collection of relevant ovarian cancer models that will be useful for the evaluation of future innovative therapies. TRIAL REGISTRATION: The clinical trial has been validated by local research ethic committee on January 25th 2019 and registered at ClinicalTrials.gov with the identifier NCT03831230 on January 28th 2019, last amendment v4 accepted on July 18, 2023.

Nanoparticle-Encapsulated Epirubicin Efficacy in the Inhibition of Growth of Orthotopic Ovarian Patient-Derived Xenograft in Immunocompromised Mice.

Epirubicin hydrochloride (EPI) is an anticancer drug widely used in the treatment of many solid tumors, including ovarian cancer. Because of its anatomical location, ovarian cancer shows symptoms when it is already in an advanced stage and is thus more difficult to treat. Epirubicin hydrochloride kills cancer cells effectively, but its dose escalation is limited by its severe toxicity. By encapsulating epirubicin in dextran-based nanoparticles (POLEPI), we expected to deliver higher and thus clinically more effective doses directly to tumors, where epirubicin would be released and retained longer in the tumor. The antitumor activity of POLEPI compared to EPI was first tested ex vivo in a series of ovarian cancer patient-derived tumor xenografts (PDX). The most promising PDX was then implanted orthotopically into immunocompromised mice, and tumor growth was monitored via magnetic resonance imaging (MRI). Although we succeeded in suppressing the growth of ovarian cancer derived from a patient, in a mouse model by 70% compared to 40% via EPI in 5 days after only one injection, we could not eliminate serious side effects, and the study was terminated prematurely for humane reasons.

Transcriptome profiling of patient-derived tumor xenografts suggests novel extracellular matrix-related signatures for gastric cancer prognosis prediction.

BACKGROUND: A major obstacle to the development of personalized therapies for gastric cancer (GC) is the prevalent heterogeneity at the intra-tumor, intra-patient, and inter-patient levels. Although the pathological stage and histological subtype diagnosis can approximately predict prognosis, GC heterogeneity is rarely considered. The extracellular matrix (ECM), a major component of the tumor microenvironment (TME), extensively interacts with tumor and immune cells, providing a possible proxy to investigate GC heterogeneity. However, ECM consists of numerous protein components, and there are no suitable models to screen ECM-related genes contributing to tumor growth and prognosis. We constructed patient-derived tumor xenograft (PDTX) models to obtain robust ECM-related transcriptomic signatures to improve GC prognosis prediction and therapy design. METHODS: One hundred twenty two primary GC tumor tissues were collected to construct PDTX models. The tumorigenesis rate and its relationship with GC prognosis were investigated. Transcriptome profiling was performed for PDTX-originating tumors, and least absolute shrinkage and selection operator (LASSO) Cox regression analysis was applied to extract prognostic ECM signatures and establish PDTX tumorigenicity-related gene (PTG) scores. The predictive ability of the PTG score was validated using two independent cohorts. Finally, we combined PTG score, age, and pathological stage information to establish a robust nomogram for GC prognosis prediction. RESULTS: We found that PDTX tumorigenicity indicated a poor prognosis in patients with GC, even at the same pathological stage. Transcriptome profiling of PDTX-originating GC tissues and corresponding normal controls identified 383 differentially expressed genes, with enrichment of ECM-related genes. A robust prognosis prediction model using the PTG score showed robust performance in two validation cohorts. A high PTG score was associated with elevated M2 polarized macrophage and cancer-associated fibroblast infiltration. Finally, combining the PTG score with age and TNM stage resulted in a more effective prognostic model than age or TNM stage alone. CONCLUSIONS: We found that ECM-related signatures may contribute to PDTX tumorigenesis and indicate a poor prognosis in GC. A feasible survival prediction model was built based on the PTG score, which was associated with immune cell infiltration. Together with patient ages and pathological TNM stages, PTG score could be a new approach for GC prognosis prediction.

Tyrosine-modified linear PEIs for highly efficacious and biocompatible siRNA delivery in vitro and in vivo.

Therapeutic gene silencing by RNA interference relies on the safe and efficient in vivo delivery of small interfering RNAs (siRNAs). Polyethylenimines are among the most studied cationic polymers for gene delivery. For several reasons including superior tolerability, small linear PEIs would be preferable over branched PEIs, but they show poor siRNA complexation. Their chemical modification for siRNA formulation has not been extensively explored so far. We generated a set of small linear PEIs bearing tyrosine modifications (LPxY), leading to substantially enhanced siRNA delivery and knockdown efficacy in vitro in various cell lines, including hard-to-transfect cells. The tyrosine-modified linear 10 kDa PEI (LP10Y) is particularly powerful, associated with favorable physicochemical properties and very high biocompatibility. Systemically administered LP10Y/siRNA complexes reveal antitumor effects in mouse xenograft and patient-derived xenograft (PDX) models, and their direct application into the brain achieves therapeutic inhibition of orthotopic glioma xenografts. LP10Y is particularly interesting for therapeutic siRNA delivery.

Metastatic seeding of human colon cancer cell clusters expressing the hybrid epithelial/mesenchymal state.

Emerging evidence supports the theory that tumor cell clusters efficiently metastasize to distant organs. However, the roles of epithelial-to-mesenchymal transition (EMT) in metastasizing tumor cell clusters have not yet been fully elucidated. To investigate this issue, tumor fragments were dissected from 40 colorectal cancer (CRC) patients and implanted subcutaneously into immunodeficient mice. We observed that tumors developed from the tumor fragments obtained from 28 of the 40 CRC patients. The tumors were then dissociated into cell suspensions to be orthotopically injected into secondary mice. The tumors from 13 of the 28 patients progressed. Furthermore, metastases formed spontaneously in the liver and lungs from the tumor fragments obtained from 8 of these 13 patients. Moreover, employing a mathematical analysis, we showed that tumor cell clusters seeded these metastases significantly more often than did single tumor cells. Membrane E-cadherin- and nuclear ZEB1-positive tumor cells indicating the hybrid epithelial/mesenchymal state were also detected in primary tumors of various CRC patients, and in the corresponding patient-derived xenografts (PDXs) and circulating tumor cell clusters in the bloodstreams of mice. In contrast, ZEB1 staining was barely detectable in the patient-matched liver metastases presumably developing through mesenchymal-to-epithelial transition. Inhibition of E-cadherin or ZEB1 expression by shRNA notably prevented the PDX-derived tumor organoids from colonizing the liver, when injected intrasplenically into mice, indicating E-cadherin and ZEB1 expressions to be required for their metastatic colonization. Taken together, these findings suggest that the epithelial/mesenchymal state mediates metastatic seeding of human CRC cell clusters into distant organs.

The mechanism and tumor inhibitory study of Lagopsis supine ethanol extract on colorectal cancer in nude mice.

BACKGROUND: This study was aimed to determination the tumor inhibitory effect and explore the potential mechanisms of Lagopsis supine ethanol extract (Ls) on colorectal cancer. METHODS: The cell growth inhibition experiment of Ls in colorectal cancer cell lines was determined by MTT method in the time course of 24, 48 and 72 h in four gradient drug concentrations. The protein expression levels of pSTAT3, pJAK2, STAT3, JAK2, Bcl-2 and caspase 3 were measured by Western blot method. The mRNA levels of the downstream genes of STAT3 were detected through semi-quantitative RT PCR. Sixty Balb/c-nude mice were xenograft with HCT116 colorectal cancer cells through subcutaneously. The xenografts were divided into five groups: model group, positive group (capecitabine 300 mg/kg) and three dosages of Ls treated groups (75, 150 and 300 mg/kg). Tumor size and tumor weight were calculated for evaluation the anti-tumor effects. H & E staining and immunohistochemical analysis were used to determine the histopathological changes and the levels of pSTAT3 and pJAK2 in the tumor tissues. RESULTS: Ls exhibited a significant anti-proliferation effect in HCT116 and SW480 cells in vitro. The protein levels of pSTAT3, pJAK2 and Bcl-2, and the mRNA levels of Bcl-2 and Bak notably reduced with a dose-dependent manner. While the protein levels of caspase 3, and mRNA levels of Bax and caspase-3 remarkably increased in the gradient dosage of Ls in HCT116 cells. HCT116 in vivo xenografts experiment showed that the growth of the tumors significantly inhibited by Ls administration, which with no any significant body weight changes in each experiment group. The histopathology analysis displayed that Ls significantly reduced the inflammatory cells in tumor tissue. Furthermore, Ls also significantly down-regulate the protein levels of pSTAT3 and pJAK2 in the tumor tissues, compared with the model group. CONCLUSIONS: This work shows that Ls inhibited the cell proliferation of colorectal cancer in vitro and significantly reduced the tumor growth in HCT116 xenografts in vivo, which is probably related with the JAK/STAT signal pathway.

3D cellular spheroids as tools for understanding carboxylated quantum dot behavior in tumors.

BACKGROUND: Monolayer cell cultures have been considered the most suitable technique for in vivo cellular experiments. However, a lot of cellular functions and responses that are present in natural tissues are lost in two-dimensional cell cultures. In this context, nanoparticle accumulation data presented in literature are often not accurate enough to predict behavior of nanoparticles in vivo. Cellular spheroids show a higher degree of morphological and functional similarity to the tissues. METHODS: Accumulation and distribution of carboxylated CdSe/ZnS quantum dots (QDs), chosen as model nanoparticles, was investigated in cellular spheroids composed of different phenotype mammalian cells. The findings were compared with the results obtained in in vivo experiments with human tumor xenografts in immunodeficient mice. The diffusive transport model was used for theoretical nanoparticles distribution estimation. RESULTS: QDs were accumulated only in cells, which were localized in the periphery of cellular spheroids. CdSe/ZnS QDs were shown to be stable and inert; they did not have any side-effects for cellular spheroids formation. Penetration of QDs in both cellular spheroids and in vivo tumor model was limited. The mathematical model confirmed the experimental results: nanoparticles penetrated only 25µm into cellular spheroids after 24h of incubation. CONCLUSIONS: Penetration of negatively charged nanoparticles is limited not only in tumor tissue, but also in cellular spheroids. GENERAL SIGNIFICANCE: The results presented in this paper show the superior applicability of cellular spheroids to cell monolayers in the studies of the antitumor effect and penetration of nanomedicines.

Initial testing (stage 1) of M6620 (formerly VX-970), a novel ATR inhibitor, alone and combined with cisplatin and melphalan, by the Pediatric Preclinical Testing Program.

BACKGROUND: M6620 is a novel inhibitor of the DNA damage repair enzyme ATR, and has potentiated the activity of cisplatin and irinotecan in non-small cell lung cancer and colon cancer xenografts, respectively. PROCEDURES: M6620 was tested in vitro at concentrations ranging from 1.0 nM to 10.0 µM and at 75 nM in combination with cisplatin or melphalan. M6620 was tested against 24 solid tumor xenografts alone and in combination with cisplatin. Cisplatin was administered intraperitoneally on days 1 and 8 at a dose of 5 mg/kg. M6620 was administered intravenously on days 2 and 9 at 20 mg/m2 approximately 16 hr after cisplatin. RESULTS: The median relative IC50 (rIC50 ) value for M6620 was 0.19 µM (range 0.03-1.38 µM). M6620 reduced the mean IC50 of cisplatin and melphalan by 1.48- and 1.95-fold, respectively. M6620 as a single agent in vivo induced significant differences in event-free survival (EFS) distribution in 5 of 24 (21%) solid tumor xenografts, but induced no objective responses. Cisplatin as a single agent induced significant differences in EFS distribution compared to control in 18 of 24 (75%) solid tumor xenografts. Three objective responses to cisplatin were observed. The M6620 and cisplatin combination induced significant differences in EFS distribution compared to control in 21 of 24 (88%), with four objective responses. CONCLUSIONS: M6620 showed modest potentiation of cisplatin and melphalan activity for some cell lines. M6620 showed little single-agent activity and the addition of M6620 to cisplatin significantly prolonged time to event for a minority of tested xenografts across several histologies.

The Antitumor Activity of a Lead Thioxanthone is Associated with Alterations in Cholesterol Localization.

The search for novel anticancer small molecules and strategies remains a challenge. Our previous studies have identified TXA1 (1-{[2-(diethylamino)ethyl]amino}-4-propoxy-9H- thioxanthen-9-one) as a hit compound, with in vitro antitumor potential by modulating autophagy and apoptosis in human tumor cell lines. In the present study, the mechanism of action and antitumor potential of the soluble salt of this molecule (TXA1.HCl) was further investigated using in vitro and mouse xenograft tumor models of NSCLC. Our results showed that TXA1.HCl affected steroid biosynthesis, increased RagD expression, and caused abnormal cellular cholesterol localization. In addition, TXA1.HCl treatment presented no toxicity to nude mice and significantly reduced the growth of human NSCLC cells xenografts in mice. Overall, this work provides new insights into the mechanism of action of TXA1, which may be relevant for the development of anticancer therapeutic strategies, which target cholesterol transport.

Wharton's jelly mesenchymal stromal cells have contrasting effects on proliferation and phenotype of cancer stem cells from different subtypes of lung cancer.

Studies on the role of multipotent mesenchymal stromal cells (MSC) on tumor growth have reported both a tumor promoting and a suppressive effect. The aim of the present study was to determine the effect of MSC isolated from Wharton's jelly of umbilical cord (WJMSC) on lung cancer stem cells (LCSC) derived from human lung tumors: two adenocarcinomas (AC) and two squamous cell carcinomas (SCC). LCSC derived from SCC and AC expressed, to varying extents, the more relevant stem cell markers. The effect of WJMSC on LCSC was investigated in vitro using conditioned medium (WJ-CM): a proliferation increase in AC-LCSC was observed, with an increase in the ALDH+ and in the CD133+ cell population. By contrast, WJ-CM hampered the growth of SCC-LCSC, with an increase in the pre-G1 phase indicating the induction of apoptosis. Furthermore, the ALDH+ and CD133+ population was also reduced. In vivo, subcutaneous co-transplantation of AC-LCSC/WJMSC generated larger tumors than AC-LCSC alone, characterized by an increased percentage of CD133+ and CD166+ cells. By contrast, co-transplantation of WJMSC and SCC-LCSC did not affect the tumor size. Our results strongly suggest that WJMSC exert, both in vitro and in vivo, contrasting effects on LCSC derived from different lung tumor subtypes.

[Targeted Bifunctional Proteins and Hybrid Nanoconstructs for Cancer Diagnostics and Therapies].

In this review, the authors' works published within the past 5 years devoted to the development of bifunctional hybrid nanostructures based on the targeting polypeptides and nanoparticles of various origin (quantum dots, nanogold, nanodiamonds, upconversion nanoparticles, magnetic and polymer nanoparticles) as modules that ensure visualization and various damaging effects on cancer cells are surveyed and the prospects of their application in theranostics and precision medicine have been contemplated.

Cell death caused by quinazolinone HMJ-38 challenge in oral carcinoma CAL 27 cells: dissections of endoplasmic reticulum stress, mitochondrial dysfunction and tumor xenografts.

BACKGROUND: This investigation clearly clarified the synthesized and antimitotic compound, 2-(3'-methoxyphenyl)-6-pyrrolidinyl-4-quinazolinone (HMJ-38), addressing its target and precise mechanism of action. We hypothesized that HMJ-38 might sensitize apoptotic death of human oral carcinoma CAL 27 cells in vitro and inhibit xenograft tumor growth in vivo. METHODS: Cell viability was assessed utilizing MTT assay. HMJ-38-treated cells represented DNA fragmentation using agarose gel electrophoresis as further evidenced using TUNEL staining. Flow cytometric analyses, immunoblotting and quantitative RT-PCR were applied for protein and gene expression. Antitumor xenograft study was employed. RESULTS: HMJ-38 concentration- and time-dependently reduced viability of CAL 27 cells. The effect of intrinsic molecules was signalized during HMJ-38 exposure with disruption of ΔΨm, MPT pore opening and the release of various events from mitochondria undergoing cell apoptosis. HMJ-38 also markedly facilitated G2/M phase arrest. HMJ-38 stimulated the activation of CDK1 activity that modulated phosphorylation on Ser70 of Bcl-2-mediated mitotic arrest and apoptosis. HMJ-38 triggered intracellular Ca(2+) release and activated related pivotal hallmarks of ER stress. HMJ-38 in nude mice bearing CAL 27 tumor xenografts decreased tumor growth. Furthermore, HMJ-38 enhanced caspase-3 gene expression and protein level in xenotransplanted tumors. CONCLUSIONS: Early roles of mitotic arrest, unfolded protein response and mitochondria-dependent signaling contributed to apoptotic CAL 27 cell demise induced by HMJ-38. In in vivo experiments, HMJ-38 also efficaciously suppressed tumor volume in a xenotransplantation model. GENERAL SIGNIFICANCE: This finding might fully support a critical event for HMJ-38 via induction of apoptotic machinery and ER stress against human oral cancer cells.

Characterization of patient-derived tumor xenograft models of endometrial cancer for preclinical evaluation of targeted therapies.

OBJECTIVE: Endometrial carcinoma (EC) is the sixth most common cancer in women and therapies are limited for advanced and recurrent disease. Patient-derived tumor xenograft (PDTX) models are becoming popular tools in translational research because of their histological and genetic similarity to the original tumors and the ability to predict therapeutic response to treatments. Here, we established and characterized a panel of 24 EC PDTX models which includes the major histological and genetic subtypes observed in patients. METHODS: Fresh tumor tissues collected from primary, metastatic and recurrent type I and type II EC patients were engrafted in immunocompromised mice. Histology, vimentin, and cytokeratin expression were evaluated, together with Microsatellite instability (MSI), mutation profiling by Whole Exome Sequencing and copy number profiling by Whole Genome Low Coverage Sequencing. The efficacy of both PI3K and MEK inhibitors was evaluated in a model of endometrioid carcinoma harboring PTEN, PIK3CA and KRAS mutations. RESULTS: We observed good similarity between primary tumors and the corresponding xenografts, at histological and genetic level. Among the engrafted endometrioid models, we found a significant enrichment of MSI and POLE mutated tumors, compared to non-engrafted samples. Combination treatment with NVP-BEZ235 and AZD6244 showed the possibility to stabilize the tumor growth in one model originated from a patient who already received several lines of chemotherapy. CONCLUSION: The established EC PDTX models, resembling the original human tumors, promise to be useful for preclinical evaluation of novel combination and targeted therapies in specific EC subgroups.

The pseudokinase tribbles homologue-3 plays a crucial role in cannabinoid anticancer action.

Δ(9)-Tetrahydrocannabinol (THC), the major active ingredient of marijuana, and other cannabinoids inhibit tumor growth in animal models of cancer. This effect relies, at least in part, on the up-regulation of several endoplasmic reticulum stress-related proteins including the pseudokinase tribbles homologue-3 (TRIB3), which leads in turn to the inhibition of the AKT/mTORC1 axis and the subsequent stimulation of autophagy-mediated apoptosis in tumor cells. Here, we took advantage of the use of cells derived from Trib3-deficient mice to investigate the precise mechanisms by which TRIB3 regulates the anti-cancer action of THC. Our data show that RasV(12)/E1A-transformed embryonic fibroblasts derived from Trib3-deficient mice are resistant to THC-induced cell death. We also show that genetic inactivation of this protein abolishes the ability of THC to inhibit the phosphorylation of AKT and several of its downstream targets, including those involved in the regulation of the AKT/mammalian target of rapamycin complex 1 (mTORC1) axis. Our data support the idea that THC-induced TRIB3 up-regulation inhibits AKT phosphorylation by regulating the accessibility of AKT to its upstream activatory kinase (the mammalian target of rapamycin complex 2; mTORC2). Finally, we found that tumors generated by inoculation of Trib3-deficient cells in nude mice are resistant to THC anticancer action. Altogether, the observations presented here strongly support that TRIB3 plays a crucial role on THC anti-neoplastic activity. This article is part of a Special Issue entitled Lipid Metabolism in Cancer.

Xenograft and organoid models in developing precision medicine for gastric cancer (Review).

Gastric cancer (GC), a highly heterogeneous disease, has diverse histological and molecular subtypes. For precision medicine, well­characterized models encompassing the full spectrum of subtypes are necessary. Patient­derived tumor xenografts and organoids serve as important preclinical models in GC research. The main advantage of these models is the retention of phenotypic and genotypic heterogeneity present in parental tumor tissues. Utilizing diverse sequencing techniques and preclinical models for GC research facilitates accuracy in predicting personalized clinical responses to anti­cancer treatments. The present review summarizes the latest advances of these two preclinical models in GC treatment and drug response assessment.

Contrast-enhanced photon-counting micro-CT of tumor xenograft models.

Photon-counting micro computed tomography (micro-CT) offers new potential in preclinical imaging, particularly in distinguishing materials. It becomes especially helpful when combined with contrast agents, enabling the differentiation of tumors from surrounding tissues. There are mainly two types of contrast agents in the market for micro-CT: small molecule-based and nanoparticle-based. However, despite their widespread use in liver tumor studies, there is a notable gap in research on the application of these commercially available agents for photon-counting micro-CT in breast and ovarian tumors. Herein, we explored the effectiveness of these agents in differentiating tumor xenografts from various origins (AU565, MDA-MB-231, and SKOV-3) in nude mice, using photon-counting micro-CT. Specifically, ISOVUE-370 (a small molecule-based agent) and Exitrone Nano 12000 (a nanoparticle-based agent) were investigated in this context. To improve tumor visualization, we proposed a novel color visualization method for photon-counting micro-CT, which changes color tones to highlight contrast media distribution, offering a robust alternative to traditional material decomposition methods with less computational demand. Our in vivo experiments confirm its effectiveness, showing distinct enhancement characteristics for each contrast agent. Qualitative and quantitative analyses suggested that Exitrone Nano 12000 provides superior vasculature enhancement and better quantitative consistency across scans, while ISOVUE-370 gives more comprehensive tumor enhancement but with a significant variance between scans due to its short blood half-time. This variability leads to high sensitivity to timing and individual differences among mice. Further, a paired t-test on mean and standard deviation values within tumor volumes showed significant differences between the AU565 and SKOV-3 tumor models with the nanoparticle-based (p-values < 0.02), attributable to their distinct vascularity, as confirmed by immunohistochemistry. These findings underscore the utility of photon-counting micro-CT in non-invasively assessing the morphology and anatomy of different tumor xenografts, which is crucial for tumor characterization and longitudinal monitoring of tumor development and response to treatments.

Contrast-enhanced photon-counting micro-CT of tumor xenograft models.

Objective. Photon-counting micro-computed tomography (micro-CT) is a major advance in small animal preclinical imaging. Small molecule- and nanoparticle-based contrast agents have been widely used to enable the differentiation of liver tumors from surrounding tissues using photon-counting micro-CT. However, there is a notable gap in the application of these market-available agents to the imaging of breast and ovarian tumors using photon-counting micro-CT. Herein, we have used photon-counting micro-CT to determine the effectiveness of these contrast agents in differentiating ovarian and breast tumor xenografts in live, intact mice.Approach. Nude mice carrying different types of breast and ovarian tumor xenografts (AU565, MDA-MB-231 and SKOV-3 human cancer cells) were injected with ISOVUE-370 (a small molecule-based agent) or Exitron Nano 12000 (a nanoparticle-based agent) and subjected to photon-counting micro-CT. To improve tumor visualization using photon-counting micro-CT, we developed a novel color visualization method, which changes color tones to highlight contrast media distribution, offering a robust alternative to traditional material decomposition methods with less computational demand.Main results. Ourin vivoexperiments confirm the effectiveness of this color visualization approach, showing distinct enhancement characteristics for each contrast agent. Qualitative and quantitative analyses suggest that Exitron Nano 12000 provides superior vasculature enhancement and better quantitative consistency across scans, while ISOVUE-370 delivers a more comprehensive tumor enhancement but with significant variance between scans due to its short blood half-time. Further, a paired t-test on mean and standard deviation values within tumor volumes showed significant differences between the AU565 and SKOV-3 tumor models with the nanoparticle-based contrast agent (p-values < 0.02), attributable to their distinct vascularity, as confirmed by immunohistochemical analysis.Significance. These findings underscore the utility of photon-counting micro-CT in non-invasively assessing the morphology and anatomy of different tumor xenografts, which is crucial for tumor characterization and longitudinal monitoring of tumor progression and response to treatments.

Application of a Specific and Sensitive NQO1 Turn-On Near-Infrared Fluorescence Probe for Live Cancer Cell and Xenografted Tumor Imaging in Nude Mice.

Sensitive activity stains for enzymes selectively expressed in human cancers offer valuable tools for imaging with wide applications in experimental, diagnostic, and therapeutic settings. The scant expression of the antioxidant enzyme NQO1 in normal tissues and its great abundance in malignant counterparts due to the increased redox stress and hypoxia is one such example. Previously, we described a potent nontoxic probe that remains nonfluorescent but releases an intense fluorogenic compound after intracellular cleavage by NQO1 catalysis. This infrared probe with a 644 nm emission has excellent tissue penetrating ability and low background absorption. Described here are methods (fluorescence microscopy, flow cytometry, and in vivo animal imaging) to rapidly image NQO1 activity in hypoxic and non-hypoxic cancer cells and tumors developed in live mouse xenograft models. The specificity of the dye for NQO1 in all three procedures was verified, and the methods should be useful for both in vitro and in vivo studies.

Quantification of Tumor and Angiogenesis-Related Markers in Ovarian Cancer Models by a Digital Pathology Approach.

Digital pathology has the potential to quantify tumor markers accurately and reproducibly with various cellular and subcellular localizations in tissues, thus filling a need in cancer research. As a case study, we quantified the percentage of necrosis, microvessels density, and monocarboxylate transporter 4 (MCT4) expression in two ovarian cancer patient-derived xenograft (PDX) models subcutaneously injected in NOD/SCID mice. PDX models were treated with bevacizumab, an antiangiogenic drug, that targets vascular endothelial growth factor A (VEGF-A). Specific signal analysis algorithms allowed us to study morphologic, vascular, and metabolic modifications induced by antiangiogenic therapy by a quantitative, reproducible, and reliable approach.