Liver Cancer Xenograft Model Research Articles

KCTD17-mediated Ras stabilization promotes hepatocellular carcinoma progression.

Potassium channel tetramerization domain containing 17 (KCTD17) protein, an adaptor for the cullin3 (Cul3) ubiquitin ligase complex, has been implicated in various human diseases; however, its role in hepatocellular carcinoma (HCC) remains elusive. Here, we aimed to elucidate the clinical features of KCTD17, and investigate the mechanisms by which KCTD17 affects HCC progression. We analyzed transcriptomic data from patients with HCC. Hepatocyte-specific KCTD17 deficient mice were treated with diethylnitrosamine (DEN) to assess its effect on HCC progression. Additionally, we tested KCTD17-directed antisense oligonucleotides for their therapeutic potential in vivo. Our investigation revealed the upregulation of KCTD17 expression in both tumors from patients with HCC and mouse models of HCC, in comparison to non-tumor controls. We identified the leucine zipper-like transcriptional regulator 1 (Lztr1) protein, a previously identified Ras destabilizer, as a substrate for KCTD17-Cul3 complex. KCTD17-mediated Lztr1 degradation led to Ras stabilization, resulting in increased proliferation, migration, and wound healing in liver cancer cells. Hepatocyte-specific KCTD17 deficient mice or liver cancer xenograft models were less susceptible to carcinogenesis or tumor growth. Similarly, treatment with KCTD17-directed antisense oligonucleotides (ASO) in a mouse model of HCC markedly lowered tumor volume as well as Ras protein levels, compared to those in control ASO-treated mice. KCTD17 induces the stabilization of Ras and downstream signaling pathways and HCC progression and may represent a novel therapeutic target for HCC.

An oncolytic poxvirus encoding hNIS, shows anti-tumor efficacy and allows tumor imaging in a liver cancer model.

Oncolytic viruses (OVs) are live viruses that can selectively replicate in cancer cells. We have engineered an OV (CF33) to make it cancer-selective through the deletion of its J2R (thymidine kinase) gene. Additionally, this virus has been armed with a reporter gene, human sodium iodide symporter (hNIS), to facilitate non-invasive imaging of tumors using positron emission tomography (PET). In this study we evaluated the oncolytic properties of the virus (CF33-hNIS) in liver cancer model, and its usefulness in tumor imaging. The virus was found to efficiently kill liver cancer cells and the virus-mediated cell death exhibited characteristics of immunogenic death based on the analysis of 3 damage associate molecular patterns (DAMPs): calreticulin, ATP and HMGB1. Furthermore, local or systemic administration of a single dose of the virus showed anti-tumor efficacy against a liver cancer xenograft model in mice and significantly increased survival of treated mice. Lastly, PET scanning was performed following injection of the radioisotope I-124, for imaging of tumors, and a single dose of virus as low as 1E03 pfu, administered intratumorally (I.T.) or intravenously (I.V.), allowed for PET imaging of tumors. In conclusion, CF33-hNIS is safe and effective in controlling human tumor xenografts in nude mice, and it also facilitates non-invasive imaging of tumors.

Therapeutic effects of TM4SF5-targeting chimeric and humanized monoclonal antibodies in hepatocellular and colon cancer models

The transmembrane 4 L six family member 5 (TM4SF5) is aberrantly expressed in hepatocellular and colorectal cancers, and has been implicated in tumor progression, suggesting that it could serve as a novel therapeutic target. Previously, we screened a murine antibody phage-display library to generate a novel monoclonal antibody, Ab27, that is specific to the extracellular loop 2 of TM4SF5. In this study, we evaluated the effects of chimeric Ab27 using cancer cells expressing endogenous TM4SF5 or stably overexpressing TM4SF5 in vivo and in vitro. Monotherapy with Ab27 significantly decreased tumor growth in liver and colon cancer xenograft models, including a sorafenib-resistant model, and decreased the phosphorylation of focal adhesion kinase (FAK), p27Kip1, and signal transducer and activator of transcription 3 (STAT3). No general Ab27 toxicity was observed in vivo. Combination treatment with Ab27 and sorafenib or doxorubicin exerted higher antitumor activity than monotherapy. In addition, we humanized the Ab27 sequence by the complementarity-determining region (CDR) grafting method. The humanized antibody Ab27-hz9 had reduced immunogenicity but exhibited target recognition and antitumor activity comparable with those of Ab27. Both Ab27 and Ab27-hz9 efficiently targeted tumor cells expressing TM4SF5 in vivo. These observations strongly support the further development of Ab27-hz9 as a novel therapeutic agent against liver and colorectal cancers.

Autophagic Inhibition of Caveolin-1 by Compound Phyllanthus urinaria L. Activates Ubiquitination and Proteasome Degradation of β-catenin to Suppress Metastasis of Hepatitis B-Associated Hepatocellular Carcinoma.

Compound Phyllanthus urinaria L. (CP) is a traditional Chinese medicine (TCM) formula for cancer treatment in the clinic, particularly during progression of hepatitis B-associated hepatocellular carcinoma (HBV-associated HCC). Nevertheless, its anti-metastatic action and mechanisms are not well elucidated. In this study, CP was found to exert remarkable inhibitory effects on the proliferation, migration and invasion of HBV-associated HCC cells. The following network and biological analyses predicted that CP mainly targeted Caveolin-1 (Cav-1) to induce anti-metastatic effects, and Wnt/β-catenin pathway was one of the core mechanisms of CP action against HBV-associated HCC. Further experimental validation implied that Cav-1 overexpression promoted metastasis of HBV-associated HCC by stabilizing β-catenin, while CP administration induced autophagic degradation of Cav-1, activated the Akt/GSK3β-mediated proteasome degradation of β-catenin via ubiquitination activation, and subsequently attenuated the metastasis-promoting effect of Cav-1. In addition, the anti-cancer and anti-metastatic action of CP was further confirmed by in vivo and ex vivo experiments. It was found that CP inhibited the tumor growth and metastasis of HBV-associated HCC in both mice liver cancer xenograft and zebrafish xenotransplantation models. Taken together, our study not only highlights the novel function of CP formula in suppressing metastasis of HBV-associated HCC, but it also addresses the critical role of Cav-1 in mediating Akt/GSK3β/β-catenin axis to control the late-phase of cancer progression.

A recombinant Newcastle disease virus expressing MMP8 promotes oncolytic efficacy

Oncolytic virus is an emerging anti-cancer strategy. However, extracellular matrix (ECM), as a physical barrier, limits virus spread within the tumor. To overcome the obstacle, we constructed a recombinant Newcastle disease virus (NDV) expressing matrix metalloproteinase (MMP8) (NDV-MMP8) using with reverse genetic technology. In vitro, NDV-MMP8 was identified and verified by WB and ELISA. Cell viability was detected by CCK-8 assay. In vivo, we established two liver cancer xenograft models. NDV-MMP8 was injected into the tumor to observe the tumor volume and survival of mice. The changes in extracellular matrix were observed by Masson's trichrome staining. Virus expression in tumor tissues was detected by immunofluorescence assay. The virus titer in tumor tissues was detected by TCID50. Histopathological changes were detected by hematoxylin and eosin (HE) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Intratumoral administration of NDV-MMP8 can effectively degrade ECM, promote the spread of the virus within the tumor, and reduce tumor growth rate. Therefore, the method of increasing intratumoral virus accumulation by degradation of the ECM to enhance the oncolytic effect has great potential for clinical application.

Sex-dependent liver cancer xenograft models for predicting clinical data in the evaluation of anticancer drugs

BackgroundThe incidence and mortality of liver cancer show a great difference between the sexes. We established sex-dependent liver cancer xenograft models and investigated whether such sex-dependent models could be used to simultaneously evaluate the therapeutic and adverse effects of anticancer drugs for drug screening.ResultsIn the in-vitro test, the cytotoxicity of anticancer drugs (cisplatin, 5-fluorouracil, and doxorubicin) was compared between male- and female-derived liver cancer cell lines. Cisplatin and 5-fluorouracil exhibited cytotoxicity without sex-difference, but doxorubicin showed dose-dependently significant cytotoxicity only in male-derived cells. Our results showed a strong correlation between preclinical and clinical data with the use of sex-dependent liver cancer xenograft models. Moreover, the male-derived Hep3B-derived xenograft model was more sensitive than the female-derived SNU-387-derived xenograft model against doxorubicin treatment. Doxorubicin showed more severe cardiotoxicity in the male xenograft model than in the female model. We investigated the occurrence frequency of doxorubicin-related cardiotoxicity using data obtained from the Korea Institute of Drug Safety & Risk Management Database, but no significant difference was observed between the sexes.ConclusionsOur results suggest that sex-dependent xenograft models are useful tools for evaluating the therapeutic and adverse effects of anticancer drugs, because sex is an important consideration in drug development.

Construction of a new patient-derived xenograft model of human liver cancer in mice with normal immunity

Objective To establish a new patient-derived xenograft (PDX) model of human liver cancer by inoculating the complex of human primary liver cancer cells and a novel microcarrier (microcarrier 6) into mice with normal immune function. Methods Primary liver cancer cells were isolated and extracted from the fresh human liver cancer tissue of five patients and were then co-cultured with microcarrier 6 to construct a three-dimensional tumor cell culture model in vitro. According to the type of graft, 75 male C57BL/6 mice were divided into cell control group, microcarrier control group, and experimental group (each sample corresponded to three groups, with 15 groups in total and 5 mice in each group). The liver cancer cell-microcarrier complex was implanted into the mice by subcutaneous inoculation, and tumor formation time, tumor formation rate, and histopathological manifestations were observed. The Fisher's exact test was used for comparison of categorical data between two groups. Results As for the liver cancer cells from the five patients, tumor formation was observed in the mice corresponding to three patients. In these three experiments, tumor formation was not observed in the control groups and was only observed in the experimental groups, and 12 of the 15 mice in the experimental groups had successful tumor formation, with a tumor formation rate as high as 80%, which was significantly different from that in the cell control groups and the microcarrier control groups (all P Conclusion This experiment successfully establishes a new PDX model of human liver cancer based on the complex of microcarrier 6 and human primary liver cancer cells in mice with normal immunity. This model can be used to better elucidate the mechanism of the development and progression of liver cancer in the body with normal immunity, and besides, it also provides a new animal model with higher value for the precise treatment of liver cancer.

Therapeutic effects of boronate ester cross-linked injectable hydrogels for the treatment of hepatocellular carcinoma.

Hepatocellular carcinoma is the most common malignancy with a high incidence rate and is the leading cause of cancer-related deaths. Herein, we developed a thermo-responsive hydrogel comprising poly(ε-caprolactone-co-lactide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-lactide (PCLA) that exhibits acidity-accelerated delivery of the tumor-targeting glucuronic acid-bearing doxorubicin (DOX-pH-GA) conjugate into tumor tissues. The PCLA copolymer was post-modified with boronic acid (BA-PCLA) to covalently cross-link with the pH-responsive DOX-pH-GA conjugate. The BA-PCLA copolymer effectively coordinated with the DOX-pH-GA conjugate through the boronate ester formation and showed a lower critical gelation temperature. The DOX conjugated via boronate ester exhibited a sustained release in vitro. Subcutaneous administration of PCLA copolymers formed in situ gels in the subcutaneous layers of Sprague-Dawley rats and degraded after 6 weeks. Similarly, BA-PCLA copolymers coordinated with DOX-pH-GA formed a stable in situ gel in vivo. In vivo imaging studies demonstrated that DOX-pH-GA was released in a sustained manner. The anti-tumor activity of the DOX releasing injectable hydrogel was examined using a HepG2 liver cancer xenograft model. The in vivo antitumor effect demonstrated that the DOX releasing hydrogel depot remarkably suppresses the tumor growth. These results demonstrate that the pH-responsive DOX releasing thermo-responsive hydrogel depot has great potential for application in localized anticancer therapy.

URM1 Promoted Tumor Growth and Suppressed Apoptosis via the JNK Signaling Pathway in Hepatocellular Carcinoma.

ObjectiveUbiquitin-related modifier 1 (URM1) is a member of the ubiquitin-like regulator family, which acts as a post-translational protein modifier in the oxidative emergency response mechanism. Previous studies have shown that URM1 may be involved in the process of apoptosis and may play a role in JNK signaling pathway. In this study, we aimed to investigate the role and possible mechanism of URM1 in HCC progression.Patients and MethodsExpression of URM1 was determined in 90 pairs of matched liver cancer and adjacent non-cancerous tissues by immunohistochemistry. The impacts of URM1 on HCC cell proliferation, apoptosis, migration and invasion capacities were verified by CCK-8, colony formation, TUNEL staining, wound healing assay and transwell, respectively. Then, the effect of URM1 on subcutaneous tumor formation in vitro was explored by nude mouse xenograft model of liver cancer. Finally, the expression of apoptosis-related proteins was analyzed in URM1 knockdown samples by Western blotting.ResultsIn this study, compared with paired adjacent non-cancerous tissues, the expression of URM1 was higher in liver cancer tissues (P <0.01). Kaplan–Meier survival analysis showed that high URM1 expression was significantly associated with poor prognosis (P <0.05). Moreover, URM1 knockdown inhibited liver cancer cell proliferation and migration. Furthermore, URM1 knockdown promoted apoptosis of liver cancer cells. At the same time, URM1 knockdown inhibited tumor growth in nude mouse xenograft model of liver cancer. In addition, URM1 knockdown downregulated the expression of the apoptosis-related factors JNK1/2 and TP53 and upregulated the phosphorylation of JNK1/2 and P53.ConclusionIn summary, our results suggested that URM1 expression is increased in liver cancer tissues, and URM1 knockdown inhibits the proliferation and migration of liver cancer cells and accelerates apoptosis. High URM1 expression is associated with poor prognosis in patients with HCC.

Delivery of triptolide with reduction-sensitive polymer nanoparticles for liver cancer therapy on patient-derived xenografts models

Hepatocellular carcinoma (HCC) has become the fourth predominant cause of cancer-related deaths worldwide, and HCC is still one of the worst prognoses for survival as it is poorly responsive to both chemotherapy and surgical treatment due to drug resistance and great toxic effects. Triptolide (TP), a key ingredient from the traditional Chinese medical herb, has been utilized to treat inflammation and antitumor for centuries. However, investigations of this potent agent have been met with only limited success due to the severe systemic toxicities in patients and low water solubility as well as its high toxicity over the past two decades. Herein, we reported the development of a reduction-responsive drug delivery system loaded with TP for glutathione (GSH)-triggered drug release for cancer therapy. With the GSH-sensitive TP loaded nanoparticles, the remarkable increases in tumor accumulation and amelioration of drug toxicity in animals are demonstrated, which is likely due to sustained stepwise release of active TP within cancer cells. Moreover, in a patient-derived tumor xenograft model of liver cancer, administration of tritolide nanoparticles enhances the antitumor efficacy relative to administration of free TP. These findings indicate that GSH-sensitive release of TP may be a promising strategy for cancer treatment.

Sex-dependent effects of estrogen pellets in human liver cancer xenograft models.

Liver cancer shows noticeable differences in the incidence rate and mortality between genders. To investigate the estrogen effect on tumor progression in liver cancer, we developed a xenograft model using estrogen pellets. SK-Hep1 cells (human male liver carcinoma) were inoculated into male or female nude mice. Subsequently, estrogen pellets were subcutaneously implanted into these xenograft models. Interestingly, the marked adverse effect of estrogen pellets (0.5mg/21days) were observed in the male-derived xenograft model, with increased ulcerative dermatitis in male mice than in female mice. Additionally, necrosis was observed in male mice with SK-Hep1-derived tumors. However, the estrogen pellet (0.5mg/60days) did not exhibit these adverse effects. Tumor growth in female mice was significantly suppressed by estrogen (0.5mg/60days). Tumor growth was also suppressed in male mice implanted with estrogen (0.5mg/60days), but the suppression was not significant. We found that estrogen-induced skin damage was more severe in male mice than female mice. The tumor suppression of estrogen was effective in female mice compared to male mice bearing liver cancer. The results suggest that the sex difference affects estrogen activity and thus should be considered in the preclinical assessment.

Indium-111 labeled bleomycin for targeting diagnosis and therapy of liver tumor: optimized preparation, biodistribution and SPECT imaging with xenograft models

In this work, the preparation of 111In radiolabeled bleomycin (111In-BLM) was optimized systematically and used for SPECT imaging of liver cancer xenograft models. 111In-BLM with a high radiochemical yield (> 99%) could be obtained at pH 0.5–1 at a mixture ratio of 9:1 (111In/BLM, mCi/mg). The radiochemical purity of 111In-BLM retained > 99% in either buffers or serum for 3 days. Biodistribution of 111In-BLM revealed its excellent stability in vivo. The SPECT imaging studies showed 111In-BLM has great specificity to liver tumor xenograft. All the results implied 111In-BLM is a potential radiopharmaceutical for targeting diagnosis and therapy of liver tumor.

Anti-GPC3 Antibody Tagged Cationic Switchable Lipid-Based Nanoparticles for the Co-Delivery of Anti-miRNA27a And Sorafenib in Liver Cancers.

The immediate plasma metabolism and development of chemo-resistance (single agent) severely hampers the clinical effectiveness of Sorafenib (SRF) in liver cancer therapy. MicroRNA27a inhibition is a promising biological strategy for breast cancer therapy. In this study, we aimed to prepare SRF and anti-miRNA27a-loaded anti-GPC3 antibody targeted lipid nanoparticles to enhance the therapeutic efficacy against liver cancers. In this study, we have employed a unique cationic switchable lipid (CSL) as a mean to encapsulate miRNA as well as to confer pH-responsiveness to the nanocarrier system. The G-S27LN was nanosized and offered a pH-responsive release of SRF from the carrier system and we have demonstrated the specific affinity of G-S27LN towards the GPC3-overexpressed HepG2 cancer cells. Anti-microRNA27a significantly increased the protein expression of FOXO1 and PPAR-γ which are crucial components involved in proliferation and apoptosis of tumor cells. Combination of SRF and anti-miRNA27a (G-S27LN) resulted in significantly lower cell viability with a marked increase in the apoptosis cell proportion compared to that of free SRF indicating the synergistic anticancer effect. Animal studies in liver cancer xenograft model demonstrated significant suppression of tumor burden, reduced tumor cell and elevated TUNEL positive apoptosis with no toxicity concerns in animals treated with G-S27LN formulation. The CSL-based G-S27LN efficiently co-delivered anti-microRNA27a and SRF and therefore represents a promising therapy to treat liver cancer. This study also brings forth a platform strategy for the effective treatment of number of other advanced cancers.

Abstract 4377: Liver X receptor mediated lipotoxicity represents a treatment option for liver cancer

Abstract Solid tumors evolve significant changes in metabolic pathways during development by virtue of their specific biosynthetic demands, their particular microenvironment and the potential occurrence of toxic metabolites such as reactive oxygen species. However, the development of cancer treatment approaches that are based on the inhibition of biosynthetic routes is impaired due to the high plasticity of metabolic networks, e.g. resulting in activation of compensatory pathways or in an increased exchange of metabolites between cancer cells and the tumor environment. Therefore, such therapies could not be translated into efficient clinical applications so far. Here we show that an enhanced lipogenesis, triggered by a pharmacological activation of the Liver X receptor (LXR), represents a new therapeutic strategy for the treatment of liver carcinoma (HCC). A combination of LXR mediated fatty acid synthesis and concomitant Raf suppression results in oxidative stress, induction of a critical ER stress response and subsequently in apoptosis of different murine and human liver cancer cells. Our mechanistic studies identified Raf as an important regulator of lipid metabolism in liver cancer. We found that Raf-1 directly interacts with Stearoyl-CoA desaturase-1 (Scd1), the central enzyme for the conversion of saturated into mono-unsaturated fatty acids and thereby maintains Scd1 protein stability in HCC cells. Thus, inhibition of Raf by Sorafenib diminished Scd1 protein abundance leading to toxic accumulation of saturated fatty acids and metabolic stress in cancer cells under sustained lipogenesis. Treatment studies in autochthonous liver cancer mouse models and xenograft models of human HCC revealed that a combinatorial therapy, consisting of the LXR agonist T0901317 and Sorafenib is highly potent to suppress liver cancer development and to extend the survival of tumor bearing animals. Such a therapy was efficient against hepatic neoplasia with different metabolic phenotypes and well tolerated by mice, even by animals that already suffer from a fatty liver disease. Taken together, we here propose a pharmacologically induced accumulation of toxic metabolites in cancer cells as a new strategy for efficient metabolic targeting of therapy refractory solid tumors. Citation Format: Ramona Rudalska, Jule Harbig, Marteinn Snaebjoernsson, Lyudmyla Taranets, Florian Heinzmann, Stefan Zwirner, Wei Ciu Hu, Thales Kronenberger, Tae-Won Kang, Antti Poso, Stefan Laufer, Mathias Rosenfeldt, Nisar P. Malek, Bernd Pichler, Nikita Popov, Almut Schulze, Lars Zender, Daniel Dauch. Liver X receptor mediated lipotoxicity represents a treatment option for liver cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4377.

Kidney-Type Glutaminase Inhibitor Hexylselen Selectively Kills Cancer Cells via a Three-Pronged Mechanism.

Tumor metabolism has been deeply investigated for cancer therapeutics. Here, we demonstrate that glutamine deficiency alone could not completely inhibit cancer cell growth and that many potent kidney-type glutaminase (KGA) inhibitors did not show satisfying in vivo efficacy. The potent KGA allosteric inhibitor, CB-839, resulted in up to 80% growth inhibition of all tested cell lines, whereas Hexylselen (CPD-3B), a KGA/glutamate dehydrogenase (GDH) inhibitor, showed essentially no toxicity to normal cells up to a 10 μM concentration and could completely inhibit the growth of many aggressive cell lines. Further analyses showed that CPD-3B targets not only KGA and GDH but also thioredoxin reductase (TrxR) and amidotransferase (GatCAB), which results in corresponding regulation of Akt/Erk/caspase-9 signaling pathways. In an aggressive liver cancer xenograft model, CPD-3B significantly reduced tumor size, caused massive tumor tissue damage, and prolonged survival rate. These provide important information for furthering the drug design of an effective anticancer KGA allosteric inhibitor.

Novel 1,3,4-Selenadiazole-Containing Kidney-Type Glutaminase Inhibitors Showed Improved Cellular Uptake and Antitumor Activity.

Kidney-type glutaminase [KGA/isoenzyme glutaminase C (GAC)] is becoming an important tumor metabolism target in cancer chemotherapy. Its allosteric inhibitor, CB839, showed early promise in cancer therapeutics but limited efficacy in in vivo cancer models. To improve the in vivo activity, we explored a bioisostere replacement of the sulfur atom in bis-2-(5-phenylacetamido-1,2,4-thiadiazol)ethyl sulfide and CB839 analogues with selenium using a novel synthesis of the selenadiazole moiety from carboxylic acids or nitriles. The resulting selenadiazole compounds showed enhanced KGA inhibition, more potent induction of reactive oxygen species, improved inhibition of cancer cells, and higher cellular and tumor accumulation than the corresponding sulfur-containing molecules. However, both CB839 and its selenium analogues show incomplete inhibition of the tested cancer cells, and a partial reduction in tumor size was observed in both the glutamine-dependent HCT116 and aggressive H22 liver cancer xenograft models. Despite this, tumor tissue damage and prolonged survival were observed in animals treated with the selenium analogue of CB839.

Development of a novel zebrafish xenograft model in ache mutants using liver cancer cell lines

Acetylcholinesterase (AChE), an enzyme responsible for degradation of acetylcholine, has been identified as a prognostic marker in liver cancer. Although in vivo Ache tumorigenicity assays in mouse are present, no established liver cancer xenograft model in zebrafish using an ache mutant background exists. Herein, we developed an embryonic zebrafish xenograft model using epithelial (Hep3B) and mesenchymal (SKHep1) liver cancer cell lines in wild-type and achesb55 sibling mutant larvae after characterization of cholinesterase expression and activity in cell lines and zebrafish larvae. The comparison of fluorescent signal reflecting tumor size at 3-days post-injection (dpi) revealed an enhanced tumorigenic potential and a reduced migration capacity in cancer cells injected into homozygous achesb55 mutants when compared with the wild-type. Increased tumor load was confirmed using an ALU based tumor DNA quantification method modified for use in genotyped xenotransplanted zebrafish embryos. Confocal microscopy using the Huh7 cells stably expressing GFP helped identify the distribution of tumor cells in larvae. Our results imply that acetylcholine accumulation in the microenvironment directly or indirectly supports tumor growth in liver cancer. Use of this model system for drug screening studies holds potential in discovering new cholinergic targets for treatment of liver cancers.

Characterization and Validation of Hepatocellular Carcinoma (HCC) Xenograft tumor as a Suitable Liver Cancer Model for Preclinical Mesenchymal Stem Cell Studies

Background:Hepatocellular carcinoma (HCC) is the fifth most diagnosed cancer and the third leading cause of cancer-related death. sorafenib is used as a standard therapy to treat HCC. mesenchymal stromal cells (MSCs) have also been used to suppress HCC. Here we investigate the development of a xenograft model of liver cancer to study the homing of hpMSC-GFP cells, tumor kinetics and molecular characterizations of HCC.Methods:To create xenograft models of HCC, HepG2 cell lines were inoculated into the flanks of 9 nude mice bilaterally. Animals were then divided into three groups: the first group received hpMSC-GFP systemically, the second received intra-tumoral hpMSC-GFP and the third received PBS. The first two groups were sacrificed after 72 hours of MSCs injection but the third group was followed up for forty days. One tumor from each animal was then transferred to formalin buffer for H&E staining and immunohistochemistry analysis (KI67 and CD34), and the other tumor was used for ex-vivo imaging. Blood samples were taken from all subjects before sacrificing them.Results:Histopathological fidelity of heterotopic HePG2 xenograft models to human HCC tumors was demonstrated. Biochemical evaluation suggested the health of the animal’s liver and kidneys. Ex-vivo imaging illustrated homing of more hpMSC-GFP cells in tumor tissues derived from the group receiving intra-tumoral hpMSC-GFP.Conclusion:A standard method was used to inoculate tumor cells and the intervention was shown to be safe to liver and kidneys. Local injection of MSCs can be used as cell therapy to fight neoplasms.

The Application of Heptamethine Cyanine Dye DZ-1 and Indocyanine Green for Imaging and Targeting in Xenograft Models of Hepatocellular Carcinoma.

Near infrared fluorescence (NIRF) imaging has strong potential for widespread use in noninvasive tumor imaging. Indocyanine green (ICG) is the only Food and Drug Administration (FDA) -approved NIRF dye for clinical diagnosis; however, it is unstable and poorly targets tumors. DZ-1 is a novel heptamethine cyanine NIRF dye, suitable for imaging and tumor targeting. Here, we compared the fluorescence intensity and metabolism of DZ-1 and ICG. Additionally, we assayed their specificities and abilities to target tumor cells, using cultured hepatocellular carcinoma (HCC) cell lines, a nude mouse subcutaneous xenograft model of liver cancer, and a rabbit orthotopic transplantation model. We found that DZ-1 accumulates in tumor tissue and specifically recognizes HCC in subcutaneous and orthotopic models. The NIRF intensity of DZ-1 was one order of magnitude stronger than that of ICG, and DZ-1 showed excellent intraoperative tumor targeting in the rabbit model. Importantly, ICG accumulated at tumor sites, as well as in the liver and kidney. Furthermore, DZ-1 analog-gemcitabine conjugate (NIRG) exhibited similar tumor-specific targeting and imaging properties, including inhibition of tumor growth, in HCC patient-derived xenograft (PDX) mice. DZ-1 and NIRG demonstrated superior tumor-targeting specificity, compared to ICG. We show that DZ-1 is an effective molecular probe for specific imaging, targeting, and therapy in HCC.

Targeting Alpha-Fetoprotein (AFP)-MHC Complex with CAR T-Cell Therapy for Liver Cancer.

The majority of tumor-specific antigens are intracellular and/or secreted and therefore inaccessible by conventional chimeric antigen receptor (CAR) T-cell therapy. Given that all intracellular/secreted proteins are processed into peptides and presented by class I MHC on the surface of tumor cells, we used alpha-fetoprotein (AFP), a specific liver cancer marker, as an example to determine whether peptide-MHC complexes can be targets for CAR T-cell therapy against solid tumors. We generated a fully human chimeric antigen receptor, ET1402L1-CAR (AFP-CAR), with exquisite selectivity and specificity for the AFP158-166 peptide complexed with human leukocyte antigen (HLA)-A*02:01. We report that T cells expressing AFP-CAR selectively degranulated, released cytokines, and lysed liver cancer cells that were HLA-A*02:01+/AFP+ while sparing cells from multiple tissue types that were negative for either expressed proteins. In vivo, intratumoral injection of AFP-CAR T cells significantly regressed both Hep G2 and AFP158-expressing SK-HEP-1 tumors in SCID-Beige mice (n = 8 for each). Moreover, intravenous administration of AFP-CAR T cells in Hep G2 tumor-bearing NSG mice lead to rapid and profound tumor growth inhibition (n = 6). Finally, in an established intraperitoneal liver cancer xenograft model, AFP-CAR T cells showed robust antitumor activity (n = 6). This study demonstrates that CAR T-cell immunotherapy targeting intracellular/secreted solid tumor antigens can elicit a potent antitumor response. Our approach expands the spectrum of antigens available for redirected T-cell therapy against solid malignancies and offers a promising new avenue for liver cancer immunotherapy. Clin Cancer Res; 23(2); 478-88. ©2016 AACR.