Use of Biologics for the Treatment of Inflammatory Conditions of the Pouch: A Systematic Review

BACKGROUND

Patients with medically-refractory ulcerative colitis or advanced neoplasia are often offered an ileal-pouch-anal anastomosis to restore bowel continuity. However, up to 50% of patients can suffer from inflammatory conditions of the pouch, some of which require biological therapy to treat. The aim of this study was to determine the efficacy of each biological agent for the treatment of inflammatory conditions of the pouch.

MATERIALS AND METHODS

A comprehensive literature search was performed in the major databases from inception through February 11, 2020, for studies assessing the efficacy of biologics in chronic antibiotic-refractory pouchitis (CARP) and Crohn's disease (CD) of the pouch. Both prospective and retrospective studies were included. The primary outcomes of interest were complete and partial responses were defined within each study. χ 2 test was used to compare variables.

RESULTS

Thirty-four studies were included in the systematic review and meta-analysis. Sixteen studies (N=247) evaluated the use of infliximab (IFX), showing complete response in 50.7% and partial response in 28.1% for CARP, and complete response in 66.7% and partial response in 20% for CD of the pouch. Seven studies (n=107) assessed the efficacy of adalimumab. For CARP, 33.3% of patients had a complete response, and 38.1% had a partial response, whereas for CD of the pouch, 47.7% experienced a complete response, and 24.6% had a partial response. Three studies (n=78) reported outcomes with the use of ustekinumab, showing 50% complete response and 3.8% partial response for CARP. For the CD of the pouch, 5.8% had a complete response and 78.8% had a partial response. Seven studies (n=151) reported the efficacy of vedolizumab, showing 28.4% complete response and 43.2% partial response in patients with CARP, whereas 63% of patients experienced partial response in CD of the pouch. IFX had higher rates of complete response in CARP compared with adalimumab ( P =0.04) and compared with vedolizumab ( P =0.005), but not compared with ustekinumab ( P =0.95). There were no new safety signals reported in any of the studies.

CONCLUSIONS

Biologics are safe and efficacious in the treatment of chronic, refractory inflammatory conditions of the pouch. IFX seems to be more efficacious than adalimumab and vedolizumab for CARP. Further prospective, head-to-head evaluations are needed to compare biological therapies in the treatment of CARP and CD of the pouch.

PSMA-Targeted PET Radiotracer [18F]DCFPyL as an Imaging Biomarker in Inflammatory Bowel Disease

Background

Prostate-specific membrane antigen (PSMA) is highly and specifically upregulated in active-inflamed mucosa of patients with inflammatory bowel disease (IBD). We hypothesized that this upregulation would be detectable using a PSMA-targeted positron emission tomography/computed tomography (PET/CT) imaging agent, [18F]DCFPyL, enabling non-invasive visualization of inflammation. A noninvasive means of detecting active inflammation would have high clinical value in localization and management of IBD.

Study

We performed [18F]DCFPyL imaging in three IBD patients with active disease. Abnormally increased gastrointestinal [18F]DCFPyL uptake was observed in areas with endoscopic, histologic, and immunohistochemical inflammation, demonstrating partial overlap of segments of bowel with abnormal [18F]DCFPyL uptake and active inflammation.

Conclusion

This study demonstrates that PSMA-targeted [18F]DCFPyL PET can effectively detect regions of inflamed mucosa in patients with IBD, suggesting its utility as a non-invasive imaging agent to assess location, extent, and disease activity in IBD.

Extracellular Vesicles in Hepatocellular Carcinoma: Progress and Challenges in the Translation from the Laboratory to Clinic

Extracellular vesicles (EVs) play critical roles in intercellular communication by transporting bioactive cargo to recipient cells. EVs have been implicated in a range of physiological and pathological processes, including tumor progression, metastasis, immune modulation, and drug resistance. The objective of this review is to present a thorough overview of recent studies focusing on EVs in hepatocellular carcinoma (HCC), with an emphasis on their potential utility as diagnostic biomarkers as well as therapeutic agents. Initially, we explore the utility of EVs as diagnostic biomarkers for HCC, followed by a discussion of their potential as carriers of therapeutic payloads. Additionally, we delve into the emerging field of therapeutic EVs for modulating tumor immune responses. Through this review, our ultimate aim is to provide a comprehensive understanding of the opportunities and challenges in the clinical translation of EV research in the domain of HCC.

Antibody Kinetics after Three Doses of SARS-CoV-2 mRNA Vaccination in Patients with Inflammatory Bowel Disease

Background: The emergence of new SARS-CoV-2 variants calls for more data on SARS-CoV-2 mRNA vaccine response. Aims: We aimed to assess the response to a third mRNA vaccine dose against SARS-CoV-2 in inflammatory bowel disease (IBD) patients. Methods: This was a single-center, observational prospective study of IBD patients who received a third mRNA vaccine dose against SARS-CoV-2. Antibody titers were taken post-third-dose at one and three months using the Roche Elecsys anti-SARS-CoV-2-S enzyme immunoassay. Titers less than 0.8 units/mL were considered negative according to the manufactures. Titers between 0.8 units/mL and 250 units/mL were considered non-neutralizing. Titers greater than 250 units/mL were considered neutralizing. Results: Eighty-three patients were included, all of whom had detectable antibodies at 3 months post-third dose. A total of 89% showed neutralizing and 11% non-neutralizing titers. Participants with non-neutralizing titers were more likely to be on systemic corticosteroids (p = 0.04). Two participants seroconverted from negative to positive, whereas 86% with non-neutralizing titers boosted to neutralizing levels. Only one participant with neutralizing titers after a third dose had a decrease to a non-neutralizing level within 3 months. Conclusions: Our findings support the ongoing recommendations for additional doses in immunocompromised individuals. However, longitudinal studies with a greater-sized patient population are needed.

Untethered shape-changing devices in the gastrointestinal tract

INTRODUCTION

Advances in microfabrication, automation, and computer engineering seek to revolutionize small-scale devices and machines. Emerging trends in medicine point to smart devices that emulate the motility, biosensing abilities, and intelligence of cells and pathogens that inhabit the human body. Two important characteristics of smart medical devices are the capability to be deployed in small conduits, which necessitates being untethered, and the capacity to perform mechanized functions, which requires autonomous shape-changing.

AREAS COVERED

We motivate the need for untethered shape-changing devices in the gastrointestinal tract for drug delivery, diagnosis, and targeted treatment. We survey existing structures and devices designed and utilized across length scales from the macro to the sub-millimeter. These devices range from triggerable pre-stressed thin film microgrippers and spring-loaded devices to shape-memory and differentially swelling structures.

EXPERT OPINION

Recent studies demonstrate that when fully enabled, tether-free and shape-changing devices, especially at sub-mm scales, could significantly advance the diagnosis and treatment of GI diseases ranging from cancer and inflammatory bowel disease (IBD) to irritable bowel syndrome (IBS) by improving treatment efficacy, reducing costs, and increasing medication compliance. We discuss the challenges and possibilities associated with ensuring safe, reliable, and autonomous operation of these smart devices.

Injectable, Drug-Eluting Nanocrystals Prevent Fibrosis and Stricture Formation In Vivo

BACKGROUND & AIMS

Tissue fibrosis results from uncontrolled healing responses leading to excessive mesenchymal cell activation and collagen and other extracellular matrix deposition. In the gastrointestinal tract, fibrosis leads to narrowing of the lumen and stricture formation. A drug treatment to prevent fibrosis and strictures in the gastrointestinal tract would be transformational for patient care. We aimed to develop a stricture treatment with the following characteristics and components: a small molecule with strong antifibrotic effects that is delivered locally at the site of the stricture to ensure correct lesional targeting while protecting the systemic circulation, and that is formulated with sustained-release properties to act throughout the wound healing processes.

METHODS

A high-throughput drug screening was performed to identify small molecules with antifibrotic properties. Next, we formulated an antifibrotic small molecule for sustained release and tested its antifibrotic potential in 3 animal models of fibrosis.

RESULTS

Sulconazole, a US Food and Drug Administration-approved drug for fungal infections, was found to have strong antifibrotic properties. Sulconazole was formulated as sulconazole nanocrystals for sustained release. We found that sulconazole nanocrystals provided superior or equivalent fibrosis prevention with less frequent dosing in mouse models of skin and intestinal tissue fibrosis. In a patient-like swine model of bowel stricture, a single injection of sulconazole nanocrystals prevented stricture formation.

CONCLUSIONS

The current data lay the foundation for further studies to improve the management of a range of diseases and conditions characterized by tissue fibrosis.

A Novel Patient-like Swine Model of Perianal Crohn's Disease

BACKGROUND

Perianal Crohn's disease is associated with poor outcomes and high medical costs. It is notoriously difficult to treat despite therapeutic advancements for luminal disease. A large animal model that mimics human perianal disease is needed to test innovative therapies.

OBJECTIVE

This study aimed to create a swine model that replicates the inflammatory component and therapeutic challenges found in patients with perianal Crohn's disease.

DESIGN

This was an animal preclinical study.

SETTINGS

The experiments were performed at the animal laboratory at the Johns Hopkins University.

PATIENTS

Four sus scrufus female pigs were included in the study.

INTERVENTIONS

Four female pigs underwent creation of 3 surgical perianal fistulas each, 1 rectovaginal and 2 perianal. Size 24 French setons were placed to maintain patency of the fistula tracts for 4 weeks. After removal of the setons, trinitrobenzene sulfonic acid was administered into the fistula tract to create and maintain local inflammation mimicking perianal Crohn's disease.

MAIN OUTCOMES MEASURES

An MRI was obtained to assess the fistulas and the pigs were euthanized to review histopathology.

RESULTS

Three inflammatory chronic fistula tracts were successfully created in each pig as confirmed by MRI and examination under anesthesia. This is the first report of maintaining patent fistulas in swine 2 weeks after removal of setons. For the first time, we reported that 2 pigs developed branching fistulas and small abscesses reminiscent of human perianal Crohn's disease. The corresponding histopathologic examination found significant chronic active inflammation on standard hematoxylin and eosin staining.

LIMITATIONS

The fistulas were surgically induced and did not occur naturally.

CONCLUSIONS

A chronic perianal fistula model in pigs that strongly resembles human perianal Crohn's disease was successfully created. This model can be used to test novel therapeutics and techniques to pave the path for human trials. See Video Abstract at http://links.lww.com/DCR/B969 .

UN NUEVO MODELO PORCINO SIMILAR A UN PACIENTE DE LA ENFERMEDAD DE CROHN PERIANAL ANTECEDENTES

La enfermedad de Crohn perianal se asocia con malos resultados y altos costos médicos. Es notoriamente difícil de tratar a pesar de los avances terapéuticos para la enfermedad luminal. Se precisa de un modelo animal grande que imite la enfermedad perianal humana para probar terapias innovadoras.OBJETIVO:Nuestro objetivo de este estudio fue crear un modelo porcino que replique el componente inflamatorio y los desafíos terapéuticos que se encuentran en los pacientes con enfermedad de Crohn perianal.DISEÑO:Este fue un estudio preclínico en animales.AJUSTES:Los experimentos se realizaron en el laboratorio de animales de la Universidad Johns Hopkins.PACIENTES:Se incluyeron en el estudio cuatro cerdas sus scrofa.INTERVENCIONES:Cuatro cerdas fueron sometidas a la creación de 3 fístulas perianales quirúrgicas cada una: 1 recto vaginal y 2 perianales. Se colocaron sedales de 24 French para mantener la permeabilidad de los trayectos fistulosos durante 4 semanas. Tras el retiro de los sedales, se administró ácido trinitrobenceno sulfónico en el trayecto de la fístula para crear y mantener la inflamación local simulando la enfermedad de Crohn perianal.PRINCIPALES MEDIDAS DE RESULTADOS:Se obtuvo una resonancia magnética para evaluar las fístulas y los cerdos fueron sacrificados para revisar la histopatología.RESULTADOS:Se crearon de manera exitosa tres trayectos fistulosos inflamatorios crónicos en cada cerdo, confirmados por imágenes de resonancia magnética y examen bajo anestesia. Este es el primer informe de preservación de fístulas permeables en cerdos 2 semanas tras el retiro de los setones. Por primera vez, informamos que dos cerdos desarrollaron fístulas ramificadas y pequeños abscesos que recuerdan a la enfermedad de Crohn perianal humana. El examen histopatológico correspondiente encontró una significativa inflamación crónica activa en la tinción estándar de hematoxilina y eosina.LIMITACIONES:Las fístulas se indujeron quirúrgicamente y no se produjeron de forma natural.CONCLUSIONES:Se logro recrear con éxito un modelo de fístula perianal crónica en cerdos que se asemeja mucho a la enfermedad de Crohn perianal humana. Este modelo se puede utilizar para probar nuevas terapias y técnicas para allanar el camino para los ensayos en humanos. Consulte Video Resumen en http://links.lww.com/DCR/B969 . (Traducción-Dr Osvaldo Gauto).

Initial Clinical Outcomes Using Umbilical Cord-Derived Tissue Grafts to Repair Anovaginal Fistula

BACKGROUND

Perianal fistula is a debilitating disease and challenging condition to treat. Recently, the use of stem cells has been shown to improve healing of fistulas.

OBJECTIVE

The aim was to examine the use of an umbilical cord-derived stem cell graft in a pilot study as a novel scaffold/stem inlay implanted into fistula repairs for anovaginal fistula to examine healing rates.

DESIGN

This was a pilot study.

SETTINGS

This study took place in a colorectal surgery practice.

PATIENTS

Patients with anovaginal fistula consented to participate. Cryopreserved umbilical cord tissue graft with viable cells was incorporated as an inlay using a previously reported technique by the authors. Demographic data including history of previous repairs and IBD were included. All patients were followed for a minimum of 6 weeks.

MAIN OUTCOME MEASURES

The primary measures were safety and efficacy of novel stem cell graft in the treatment of anovaginal fistula.

RESULTS

From September 2017 to September 2019, 15 patients underwent anovaginal fistula repair. Three of these patients underwent a second repair, for a total of 18 repairs. No patient was intentionally diverted, but 3 patients presented for repair with a preexisting stoma. The majority of repairs were previous repair failures (12; 67%), and 7 repairs were performed on 5 patients with IBD. Median follow-up was 30 (6-104) weeks. The safety profile for cryopreserved umbilical cord tissue graft was excellent as no adverse events occurred. Overall complete healing rate was 39%, and 12 (67%) repairs resulted in improvement of symptoms.

LIMITATIONS

This was a small pilot study.

CONCLUSIONS

This is the largest series using cryopreserved umbilical cord graft for anovaginal fistula repair. The use of umbilical cord was safe and effective at closing defects. Randomized studies are necessary to determine added benefits over current standard of care. See Video Abstract at http://links.lww.com/DCR/B896 .

RESULTADOS CLNICOS INICIALES DEL USO DE INJERTOS DE TEJIDO DERIVADO DE PLACENTA PARA REPARACIN DE FSTULAS ANOVAGINALES

ANTECEDENTES:La fístula perianal es una enfermedad debilitante y una afección difícil de tratar. Recientemente, se ha demostrado que el uso de células madre mejora la curación de las fístulas.OBJETIVO:Deseamos examinar el uso de un injerto de células madre derivadas de cordón umbilical en un estudio piloto como una nueva matriz/injerto de células madre implantado en reparaciones de fístula para fístula anovaginal para examinar las tasas de curación.DISEÑO:Este fue un estudio piloto.ESCENARIO:Este estudio se llevó a cabo en una clínica de cirugía colorrectal.PACIENTES:Se obtuvo consentimiento informado de pacientes con fístula anovaginal. El injerto de tejido de cordón umbilical criopreservado con células viables se incorporó como incrustación utilizando una técnica previamente informada por los autores. Se incluyeron datos demográficos que incluían antecedentes de reparaciones previas y enfermedad inflamatoria intestinal. Todos los pacientes fueron seguidos durante un mínimo de 6 semanas.PRINCIPALES MEDIDAS DE RESULTADO:Las principales medidas fueron la seguridad y la eficacia del nuevo injerto de células madre en el tratamiento de la fístula anovaginal.RESULTADOS:Desde 9/2017-9/2019, 15 pacientes fueron sometidas a reparación de fístula anovaginal. Tres de estos pacientes fueron sometidos a una segunda reparación, para un total de 18 reparaciones. Ningún paciente fue derivado intencionalmente mientras que 3 pacientes se presentaron para reparación con un estoma preexistente. La mayoría de las reparaciones fueron fallas de reparaciones previas (12, 67%) y se realizaron siete reparaciones en 5 pacientes con enfermedad inflamatoria intestinal (EII). La mediana de seguimiento fue de 30 semanas (6-104). El perfil de seguridad del injerto de tejido de cordón umbilical criopreservado fue excelente ya que no se produjeron efectos adversos. La tasa general de curación completa fue del 39% y 12 (67%) reparaciones dieron como resultado una mejoría de los síntomas.LIMITACIONES:Este fue un pequeño estudio piloto.CONCLUSIÓNES:Ésta es la serie más grande de utilización de injerto de cordón umbilical criopreservado para la reparación de una fístula anovaginal. La utilización del cordón umbilical resultó segura y eficaz para cerrar defectos. Se necesitan estudios aleatorizados para determinar los beneficios adicionales sobre el estándar de atención actual. Consulte Video Resumen en http://links.lww.com/DCR/B896 . (Traducción-Dr. Jorge Silva Velazco ).

A nanofiber-hydrogel composite improves tissue repair in a rat model of Crohn's disease perianal fistulas

Perianal fistulas (PAFs) represent a severe complication of Crohn's disease (CD). Despite the advent of biologic and small-molecule therapeutics for luminal disease, PAFs in CD (CD-PAF) are relatively resistant to treatment, with less than 50% responding to any therapy. We report an injectable, biodegradable, mechanically fragmented nanofiber-hydrogel composite (mfNHC) loaded with adipose-derived stem cells (ADSCs) for the treatment of fistulas in a rat model of CD-PAF. The ADSC-loaded mfNHC results in a higher degree of healing when compared to surgical treatment of fistulas, which is a standard treatment. The volume of fistulas treated with mfNHC is decreased sixfold compared to the surgical treatment control. Molecular studies reveal that utilization of mfNHC reduced local inflammation and improved tissue regeneration. This study demonstrates that ADSC-loaded mfNHC is a promising therapy for CD-PAF, and warrants further studies to advance mfNHC toward clinical translation.

Non-Viral Gene Delivery to Hepatocellular Carcinoma via Intra-Arterial Injection

Purpose

Hepatocellular carcinoma (HCC) has limited treatment options, and modest survival after systemic chemotherapy or procedures such as transarterial chemoembolization (TACE). There is therefore a need to develop targeted therapies to address HCC. Gene therapies hold immense promise in treating a variety of diseases, including HCC, though delivery remains a critical hurdle. This study investigated a new approach of local delivery of polymeric nanoparticles (NPs) via intra-arterial injection for targeted local gene delivery to HCC tumors in an orthotopic rat liver tumor model.

Methods

Poly(beta-amino ester) (PBAE) nanoparticles were formulated and assessed for GFP transfection in N1-S1 rat HCC cells in vitro. Optimized PBAE NPs were next administered to rats via intra-arterial injection with and without orthotopic HCC tumors, and both biodistribution and transfection were assessed.

Results

In vitro transfection of PBAE NPs led to >50% transfected cells in adherent and suspension culture at a variety of doses and weight ratios. Administration of NPs via intra-arterial or intravenous injection demonstrated no transfection of healthy liver, while intra-arterial NP injection led to transfection of tumors in an orthotopic rat HCC model.

Conclusion

Hepatic artery injection is a promising delivery approach for PBAE NPs and demonstrates increased targeted transfection of HCC tumors compared to intravenous administration, and offers a potential alternative to standard chemotherapies and TACE. This work demonstrates proof of concept for administration of polymeric PBAE nanoparticles via intra-arterial injection for gene delivery in rats.

Adipokine C1q/Tumor Necrosis Factor- Related Protein 3 (CTRP3) Attenuates Intestinal Inflammation Via Sirtuin 1/NF-κB Signaling

BACKGROUND & AIMS

The adipokine CTRP3 has anti-inflammatory effects in several nonintestinal disorders. Although serum CTRP3 is reduced in patients with inflammatory bowel disease (IBD), its function in IBD has not been established. Here, we elucidate the function of CTRP3 in intestinal inflammation.

METHODS

CTRP3 knockout (KO) and overexpressing transgenic (Tg) mice, along with their corresponding wild-type littermates, were treated with dextran sulfate sodium for 6-10 days. Colitis phenotypes and histologic data were analyzed. CTRP3-mediated signaling was examined in murine and human intestinal mucosa and mouse intestinal organoids derived from CTRP3 KO and Tg mice.

RESULTS

CTRP3 KO mice developed more severe colitis, whereas CTRP3 Tg mice developed less severe colitis than wild-type littermates. The deletion of CTRP3 correlated with decreased levels of Sirtuin-1 (SIRT1), a histone deacetylase, and increased levels of phosphorylated/acetylated NF-κB subunit p65 and proinflammatory cytokines tumor necrosis factor-α and interleukin-6. Results from CTRP3 Tg mice were inverse to those from CTRP3 KO mice. The addition of SIRT1 activator resveratrol to KO intestinal organoids and SIRT1 inhibitor Ex-527 to Tg intestinal organoids suggest that SIRT1 is a downstream effector of CTRP3-related inflammatory changes. In patients with IBD, a similar CTRP3/SIRT1/NF-κB relationship was observed.

CONCLUSIONS

CTRP3 expression levels correlate negatively with intestinal inflammation in acute mouse colitis models and patients with IBD. CTRP3 may attenuate intestinal inflammation via SIRT1/NF-κB signaling. The manipulation of CTRP3 signaling, including through the use of SIRT1 activators, may offer translational potential in the treatment of IBD.

Quaternary nanoparticles enable sustained release of bortezomib for hepatocellular carcinoma

BACKGROUND AND AIMS

Hepatocellular carcinoma (HCC) represents the third leading cause of cancer-related mortality in the world. Over the past two decades, there has been minimal improvement in therapies as well as clinical outcomes for patients with Barcelona Clinic Liver Cancer (BCLC)-B. These patients are treated with local interventions, including transarterial chemoembolization. Current methodologies only allow sustained intratumoral release measured in hours. Methodologies to allow sustained local release of the drug cargo over days to weeks are acutely needed. We hypothesize that tumor response as well as outcomes of patients with BCLC-B can be improved through utilization of a highly cytotoxic agent delivered with a sustained release platform.

APPROACH AND RESULTS

High-throughput drug screening across 40 HCC patient-derived organoids identified bortezomib (BTZ) as a highly cytotoxic small molecule for HCC. We designed and manufactured sustained release BTZ nanoparticles (BTZ-NP) using a flash nanocomplexation/nanoprecipitation process. We quantified the release profile and tested the anti-tumoral effects in vivo. The BTZ-NP formulation demonstrated a sustained release of BTZ of 30 days. This BTZ-NP formulation was highly effective in controlling tumor size and improved survival in vivo in three animal models of HCC, including when delivered via the hepatic artery, as we envision its delivery in patients. In addition, the BTZ-NP formulation was superior to treatment with doxorubicin-drug eluting beads.

CONCLUSIONS

The BTZ-NP formulation provides a potent and safe treatment of HCC via a localized delivery approach. These results warrant additional preclinical studies to advance this technology to human clinical trials.

Autonomous Untethered Microinjectors for Gastrointestinal Delivery of Insulin

The delivery of macromolecular drugs via the gastrointestinal (GI) tract is challenging as these drugs display low stability as well as poor absorption across the intestinal epithelium. While permeation-enhancing drug delivery methods can increase the bioavailability of low molecular weight drugs, the effective delivery of high molecular weight drugs across the tight epithelial cell junctions remains a formidable challenge. Here, we describe autonomous microinjectors that are deployed in the GI tract, then efficiently penetrate the GI mucosa to deliver a macromolecular drug, insulin, to the systemic circulation. We performed in vitro studies to characterize insulin release and assess the penetration capability of microinjectors and we measured the in vivo release of insulin in live rats. We found that the microinjectors administered within the luminal GI tract could deliver insulin transmucosally to the systemic circulation at levels similar to those with intravenously administered insulin. Due to their small size, tunability in sizing and dosing, wafer-scale fabrication, and parallel, autonomous operation, we anticipate that these microinjectors will significantly advance drug delivery across the GI tract mucosa to the systemic circulation in a safe manner.

Biostimulatory Micro-Fragmented Nanofiber-Hydrogel Composite Improves Mesenchymal Stem Cell Delivery and Soft Tissue Remodeling

Functional microgels are preferred stem cell carriers due to the ease of delivery through minimally invasive injection and seamless integration with the surrounding host tissue. A biostimulatory nanofiber-hydrogel composite (NHC) has been previously developed through covalently crosslinking a hyaluronic acid hydrogel network with surface-functionalized poly (ε-caprolactone) nanofiber fragments. The NHC mimics the microarchitecture of native soft tissue matrix, showing enhanced cell infiltration, immunomodulation, and proangiogenic properties. Here, injectability of the pre-formed NHC is improved by mechanical fragmentation, making it into micro-fragmented NHC (mfNHC) in a granular gel form as a stem cell carrier to deliver mesenchymal stem cells (MSCs) for soft tissue remodeling. The mfNHC shows a similar storage modulus but a significantly reduced injection force, as compared with the corresponding bulk NHC. When injected subcutaneously in a rat model, mfNHC-MSC constructs initiate an elevated level of host macrophage infiltration, more pro-regenerative polarization, and subsequently, improved angiogenesis and adipogenesis response when compared to mfNHC alone. A similar trend of host cell infiltration and pro-angiogenic response is detected in a swine model with a larger volume injection. These results suggest a strong potential for use of the mfNHC as an injectable carrier for cell delivery and soft tissue remodeling.

Antibody Response 3 Months After 2-Dose SARS-CoV-2 mRNA Vaccination in Patients With Inflammatory Bowel Disease

INTRODUCTION

The response to SARS-CoV-2 vaccination of patients with inflammatory bowel disease (IBD) on immune-modifying therapies requires further investigation because previous studies indicate that patients on immune therapy might have decreased antibody concentrations.

METHODS

We present the antireceptor binding domain antibody response over a period of 3 months in 217 patients with IBD who completed standard 2-dose SARS-CoV-2 mRNA vaccine series.

RESULTS

Almost all (98.6%) IBD vaccine recipients had a positive antireceptor binding domain antibody response at least 3 months after vaccination. Decreased antibody titers at 3 months were seen in a subset of patients on antitumor necrosis factor-alpha. Approximately 10% of the participants with high-titer antibodies at 1 month had a decrease to low-positive titers at 3 months, which was mostly observed in those on combination therapy and antitumor necrosis factor-alpha monotherapy.

DISCUSSION

Larger longitudinal studies are required to define the response in IBD population and its clinical impact.

Hepatobiliary tumor organoids for personalized medicine: a multicenter view on establishment, limitations, and future directions

Reliable establishment of tumor organoids is paramount to advance applications of organoid technology for personalized medicine. Here, we share our multi-center experience on initiation and tumorigenic confirmation of hepatobiliary cancer organoids. We discuss current concerns, propose potential solutions, and provide future perspectives for improvements in hepatobiliary cancer organoid establishment.

Prognostic Value of Lymph Node Ratio in Patients with Resected Synchronous Colorectal Liver Metastases and Less Than 12 Examined Lymph Nodes

BACKGROUND

Recent studies suggest that lymph node ratio (LNR) has significantly better prognostic power than N-status in patients with colorectal cancer, in particular when the number of evaluated lymph nodes (LNs) was insufficient. The aim of this study was to assess the prognostic value of LNR in patients with resected synchronous colorectal liver metastases (SCLMs) and less than 12 examined LNs.

METHODS

A prospectively maintained database of patients with resected SCLMs was queried for patients with less than 12 LNs evaluated at the time of surgery. X-tile software was used to determine the LNR cutoff value able to divide the patients in two subgroups with distinct prognosis. Overall survival (OS) and disease-free survival (DFS) rates were compared by log-rank test. A multivariate Cox regression analysis identified independent prognostic factors.

RESULTS

A cutoff LNR value of 0.22 divided patients into Low-LNR group (35 patients) and High-LNR group (36 patients). Both OS and DFS rates were significantly higher in Low-LNR group than those in High-LNR group. Independent predictors of poor OS were High-LNR (HR: 2.841, 95% CI: 1.480-5.453, p value = 0.002), bilobar SCLMs (HR: 2.253, 95% CI: 1.144-4.437, p value = 0.019) and lack of adjuvant chemotherapy (HR: 2.702, 95% CI: 1.448-5.043, p value = 0.002), while the only independent predictor of poor DFS was High-LNR (HR: 2.531, 95% CI: 1.259-5.090, p value = 0.009).

CONCLUSIONS

LNR > 0.22 was independently associated with poor OS and DFS in patients with resected SCLMs and less than 12 evaluated LNs.

Ustekinumab is effective for perianal fistulising Crohn's disease: a real-world experience and systematic review with meta-analysis

BACKGROUND

Perianal Crohn's disease (pCD) is a debilitating complication affecting up to 30% of Crohn's disease (CD) population, leading to increased morbidity, mortality and decreased quality of life. Despite the growing armamentarium of medications for luminal CD, their efficacy in pCD remains poorly studied.

AIM

To determine the efficacy of ustekinumab, a biologic approved for luminal CD, in pCD through a retrospective cohort study and systematic review.

METHODS

A retrospective cohort study on patients with CD with active perianal fistulae treated with ustekinumab from September 2013 to August 2019 was performed to determine perianal fistula response and remission at 6 and 12 months after ustekinumab induction. A systematic review was performed to further establish rates of fistula response and remission with ustekinumab.

RESULTS

At 6 months, 48.1% (13/27) patients achieved fistula response with none achieving fistula remission on provider exam, and 59.3% (16/27) achieved patient-reported symptomatic improvement with 3.7% (1/27) achieving symptomatic remission. At 1 year, on provider exam, 55.6% (5/9) had fistula response with none achieving fistula remission, and 100% (9/9) had symptomatic improvement with 22.2% (2/9) achieving symptomatic remission. There were no major safety signals during 1-year follow-up. The systematic review of 25 studies found 44% (92/209) of patients with active perianal fistulas had a clinical response within 6 months of follow-up, and 53.9% (85/152) of patients with 12 months of follow-up achieved clinical response.

CONCLUSION

Ustekinumab presents a safe and effective therapy for treatment of pCD. Prospective, randomised trials are needed to further elucidate long-term efficacy of ustekinumab for pCD.

Endoscopic-mediated, biliary hydrodynamic injection mediating clinically relevant levels of gene delivery in pig liver

BACKGROUND AND AIMS

Gene therapy could provide curative therapies to many inherited monogenic liver diseases. Clinical trials have largely focused on adeno-associated viruses (AAVs) for liver gene delivery. These vectors, however, are limited by small packaging size, capsid immune responses, and inability to redose. As an alternative, nonviral, hydrodynamic injection through vascular routes can successfully deliver plasmid DNA (pDNA) into mouse liver but has achieved limited success in large animal models.

METHODS

We explored hydrodynamic delivery of pDNA through the biliary system into the liver of pigs using ERCP and a power injector to supply hydrodynamic force. Human factor IX (hFIX), deficient in hemophilia B, was used as a model gene therapy.

RESULTS

Biliary hydrodynamic injection was well tolerated without significant changes in vital signs, liver enzymes, hematology, or histology. No off-target pDNA delivery to other organs was detected by polymerase chain reaction. Immunohistochemistry revealed that 50.19% of the liver stained positive for hFIX after hydrodynamic injection at 5.5 mg pDNA, with every hepatic lobule in all liver lobes demonstrating hFIX expression. hFIX-positive hepatocytes were concentrated around the central vein, radiating outward across all 3 metabolic zones. Biliary hydrodynamic injection in pigs resulted in significantly higher transfection efficiency than mouse vascular hydrodynamic injection at matched pDNA per liver weight dose (32.7%-51.9% vs 18.9%, P < .0001).

CONCLUSIONS

Biliary hydrodynamic injection using ERCP can achieve higher transfection efficiency into hepatocytes compared with AAVs at magnitudes of less cost in a clinically relevant human-sized large animal. This technology may serve as a platform for gene therapy of human liver diseases.

Protein synthesis inhibitor omacetaxine is effective against hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the sixth most common and the fourth most deadly cancer worldwide. The development cost of new therapeutics is a major limitation in patient outcomes. Importantly, there is a paucity of preclinical HCC models in which to test new small molecules. Herein, we implemented potentially novel patient-derived organoid (PDO) and patient-derived xenografts (PDX) strategies for high-throughput drug screening. Omacetaxine, an FDA-approved drug for chronic myelogenous leukemia (CML), was found to be a top effective small molecule in HCC PDOs. Next, omacetaxine was tested against a larger cohort of 40 human HCC PDOs. Serial dilution experiments demonstrated that omacetaxine is effective at low (nanomolar) concentrations. Mechanistic studies established that omacetaxine inhibits global protein synthesis, with a disproportionate effect on short–half-life proteins. High-throughput expression screening identified molecular targets for omacetaxine, including key oncogenes, such as PLK1. In conclusion, by using an innovative strategy, we report — for the first time to our knowledge — the effectiveness of omacetaxine in HCC. In addition, we elucidate key mechanisms of omacetaxine action. Finally, we provide a proof-of-principle basis for future studies applying drug screening PDOs sequenced with candidate validation in PDX models. Clinical trials could be considered to evaluate omacetaxine in patients with HCC.

Parameters of biliary hydrodynamic injection during endoscopic retrograde cholangio-pancreatography in pigs for applications in gene delivery

The biliary system is routinely accessed for clinical purposes via endoscopic retrograde cholangiopancreatography (ERCP). We previously pioneered ERCP-mediated hydrodynamic injection in large animal models as an innovative gene delivery approach for monogenic liver diseases. However, the procedure poses potential safety concerns related mainly to liver or biliary tree injury. Here, we sought to further define biliary hydrodynamic injection parameters that are well-tolerated in a human-sized animal model. ERCP was performed in pigs, and hydrodynamic injection carried out using a novel protocol to reduce duct wall stress. Each pig was subjected to multiple repeated injections to expedite testing and judge tolerability. Different injection parameters (volume, flow rate) and injection port diameters were tested. Vital signs were monitored throughout the procedure, and liver enzyme panels were collected pre- and post-procedure. Pigs tolerated repeated biliary hydrodynamic injections with only occasional, mild, isolated elevation in aspartate aminotransferase (AST), which returned to normal levels within one day post-injection. All other liver tests remained unchanged. No upper limit of volume tolerance was reached, which suggests the biliary tree can readily transmit fluid into the vascular space. Flow rates up to 10 mL/sec were also tolerated with minimal disturbance to vital signs and no anatomic rupture of bile ducts. Measured intrabiliary pressure was up to 150 mmHg, and fluid-filled vesicles were induced in liver histology at high flow rates, mimicking the changes in histology observed in mouse liver after hydrodynamic tail vein injection. Overall, our investigations in a human-sized pig liver using standard clinical equipment suggest that ERCP-guided hydrodynamic injection will be safely tolerated in patients. Future investigations will interrogate if higher flow rates and pressure mediate higher DNA delivery efficiencies.

Transitional changes in gastrointestinal transit and rectal sensitivity from active to recovery of inflammation in a rodent model of colitis

Patients with ulcerative colitis are typically suspected of an inflammatory flare based on suggestive symptoms of inflammation. The aim of this study was to evaluate the impact of inflammation on colonic motility and rectal sensitivity from active to recovery of inflammation. Male rats were given drinking water with 5% dextran sulfate sodium for 7 days. Inflammation, intestinal motor and sensory functions were investigated weekly for 6 weeks. (1) The disease activity index score, fecal calprotectin and tumor necrosis factor alpha were increased from Day 0 to Day 7 (active inflammation) and then decreased gradually until recovery. (2) Distal colon transit was accelerated on Day 7, and then remained unchanged. Whole gut transit was delayed on Day 7 but accelerated from Day 14 to Day 42. (3) Rectal compliance was unaffected from Day 0 to Day 7, but decreased afterwards. (4) Rectal hypersensitivity was noted on Day 7 and persistent. (5) Plasma acetylcholine was decreased on Day 7 but increased from Day 14 to Day 42. Nerve growth factor was increased from Day 7 to Day 42. DSS-induced inflammation leads to visceral hypersensitivity that is sustained until the resolution of inflammation, probably mediated by NGF. Rectal compliance is reduced one week after the DSS-induced inflammation and the reduction is sustained until the resolution of inflammation. Gastrointestinal transit is also altered during and after active colonic inflammation.

Gastrointestinal-resident, shape-changing microdevices extend drug release in vivo

Extended-release gastrointestinal (GI) luminal delivery substantially increases the ease of administration of drugs and consequently the adherence to therapeutic regimens. However, because of clearance by intrinsic GI motility, device gastroretention and extended drug release over a prolonged duration are very challenging. Here, we report that GI parasite-inspired active mechanochemical therapeutic grippers, or theragrippers, can reside within the GI tract of live animals for 24 hours by autonomously latching onto the mucosal tissue. We also observe a notable sixfold increase in the elimination half-life using theragripper-mediated delivery of a model analgesic ketorolac tromethamine. These results provide first-in-class evidence that shape-changing and self-latching microdevices enhance the efficacy of extended drug delivery.

Detection of Novel Fusion Transcript VTI1A-CFAP46 in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is now the second-highest cause of cancer death worldwide. Recent studies have discovered a wide range of somatic mutations in HCC. These mutations involve various vital signaling pathways such as: Wnt/β-Catenin, p53, telome-rase reverse transcriptase (TERT), chromatin remodeling, RAS/MAPK signaling, and oxidative stress. However, fusion transcripts have not been broadly explored in HCC.

Methods

To identify novel fusion transcripts in HCC, in the first phase of our study, we performed targeted RNA sequencing (in HCC and paired non-HCC tissues) on 6 patients with a diagnosis of HCC undergoing liver transplantation.

Results

As a result of these studies, we discovered the novel fusion transcript, VTI1A-CFAP46. In the second phase of our study, we measured the expression of wild-type VTI1A in 21 HCC specimens, which showed that 10 of 21 exhibited upregulation of wild-type VTI1A in their tumors. VTI1A (Vesicle Transport via Interaction with t-SNARE homolog 1A) is a member of the Soluble N-ethylmaleimide-Sensitive Factor (NSF) attachment protein receptor (SNARE) gene family, which is essential for membrane trafficking and function in endocytosis, autophagy, and Golgi transport. Notably, it is known that autophagy is involved in HCC.

Conclusions

The link between novel fusion transcript VTI1A-CFAP46 and autophagy as a potential therapeutic target in HCC patients deserves further investigation. Moreover, this study shows that fusion transcripts are worthy of additional exploration in HCC.

Intrahepatic Cholangiocarcinoma: Continuing Challenges and Translational Advances

Intrahepatic cholangiocarcinoma (iCCA) has over the last 10-20 years become the focus of increasing concern, largely due to its rising incidence and high mortality rates worldwide. The significant increase in mortality rates from this primary hepatobiliary cancer, particularly over the past decade, has coincided with a rapidly growing interest among clinicians, investigators, and patient advocates to seek greater mechanistic insights and more effective biomarker-driven targeted approaches for managing and/or preventing this challenging liver cancer. In addition to discussing challenges posed by this aggressive cancer, this review will emphasize recent epidemiological, basic, and translational research findings for iCCA. In particular, we will highlight emerging demographic changes and evolving risk factors, the critical role of the tumor microenvironment, extracellular vesicle biomarkers and therapeutics, intertumoral and intratumoral heterogeneity, and current and emerging targeted therapies regarding iCCA. Specifically, recent evidence linking non-bile duct medical conditions, such as nonalcoholic fatty liver disease and nonspecific cirrhosis, to intrahepatic cholangiocarcinogenesis together with geographic and ethnic variation will be assessed. Recent developments concerning the roles played by transforming growth factor-β and platelet-derived growth factor D in driving the recruitment and expansion of cancer-associated myofibroblasts within cholangiocarcinoma (CCA) stroma as well as their therapeutic implications will also be discussed. In addition, the potential significance of extracellular vesicles as bile and serum biomarkers and therapeutic delivery systems for iCCA will be described. An integrated systems approach to classifying heterogeneous iCCA subtypes will be further highlighted, and recent clinical trials and emerging targeted therapies will be reviewed, along with recommendations for future translational research opportunities. Established international CCA networks are now facilitating collaborations aimed at advancing iCCA translational and clinical research.

Human primary liver cancer organoids reveal intratumor and interpatient drug response heterogeneity

Liver cancer is the fourth leading cause of cancer-related mortality and is distinguished by a relative paucity of chemotherapy options. It has been hypothesized that intratumor genetic heterogeneity may contribute to the high failure rate of chemotherapy. Here, we evaluated functional heterogeneity in a cohort of primary human liver cancer organoid lines. Each primary human liver cancer surgical specimen was used to generate multiple cancer organoid lines, obtained from distinct regions of the tumor. A total of 27 liver cancer lines were established and tested with 129 cancer drugs, generating 3,483 cell survival data points. We found a rich intratumor, functional (drug response) heterogeneity in our liver cancer patients. Furthermore, we established that the majority of drugs were either ineffective, or effective only in select organoid lines. In contrast, we found that a subset of drugs appeared pan-effective, displaying at least moderate activity in the majority of these cancer organoid lines. These drugs, which are FDA approved for indications other than liver cancers, deserve further consideration as either systemic or local therapeutics. Of note, molecular profiles, obtained for a reduced sample set, did not correlate with the drug response heterogeneity of liver cancer organoid lines. Taken together, these findings lay the foundation for in-depth studies of pan-effective drugs, as well as for functional personalized oncology approaches. Lastly, these functional studies demonstrate the utility of cancer organoid drug testing as part of a drug discovery pipeline.

Loss of BAP1 expression is associated with genetic mutation and can predict outcomes in gallbladder cancer

Background

BRCA-1 associated protein (BAP1) is a de-ubiquitinating enzyme that regulates gene expression. Recently, the BAP1 mutation and its involvement in cancer survival have been reported in a range of tumor types, including uveal melanoma, mesothelioma, renal cancers, and biliary tract cancers. However, the frequency of BAP1 mutation and down-regulation varies among tumor types, and little is known about the function of BAP1 silencing in cancer cells. Gallbladder carcinoma (GBC) is a type of biliary tract cancer with a poor prognosis. Few mutational studies have investigated the role of BAP1 in GBC, and no functional study in vitro-, or clinical studies about cancer survival have been done.

Methods

GBC cells were studied by following the small interfering RNA mediated silencing of BAP1 with regard to proliferation, migration, invasion, and drug sensitivity. We carried out genomic, epigenomic and immunohistochemical analyses to detect somatic BAP1 alterations in 47 GBC patients undergoing surgical resection.

Results

BAP1 depletion resulted in increased migration and invasion, but not proliferation, and also resulted in decreased sensitivity to bortezomib, a proteasome inhibitor. Suppressed expression of BAP1 occurred in 22 GBC cases (46.8%) and showed a strong trend toward a worse median survival time of 13.3 months (95% CI, 17.6–62.6) (p = 0.0034). Sanger sequencing revealed a loss-of-function mutation of BAP1 in 11 out of these 22 GBC cases (50%) with low BAP1 expression, whereas 2 out of 25 GBC cases (8%) were detected in cases with high BAP1 expression. Partial changes in methylation were observed in 6 out of 47 cases, but methylation did not show a strong relationship to BAP1 expression or to the prognosis.

Conclusion

Our findings showed that genetic mutations are involved in BAP1 down-regulation, leading to promotion of the invasive character of cancer cells and poor prognosis in GBC.

Successful liver-directed gene delivery by ERCP-guided hydrodynamic injection (with videos)

BACKGROUND AND AIMS

A simple, safe, targeted, and efficient in vivo DNA delivery system is necessary for clinical-grade liver-targeted gene therapy in humans. Intravascular hydrodynamic gene delivery has been investigated in large animal models, but translation to humans has been hampered by its technical challenges, invasiveness, and potential for significant cardiovascular adverse events. We posited that intrabiliary delivery of DNA plasmids via ERCP-guided hydrodynamic injection could overcome these obstacles.

METHODS

Twelve pigs (40-50 kg) were divided into 3 groups (4 per group) and survived 21, 30, or 60 days. ERCP was performed by inflating a balloon catheter in the common hepatic duct and creating a closed space between it and the liver parenchyma. Last, a solution composed of plasmid/sleeping beauty (SB) mix was injected under pressure through the catheter into the closed space. Swine were killed at the 3 different time points and liver tissue harvested. Plasmid DNA expression and functional translated protein expression were assessed.

RESULTS

ERCP-guided hydrodynamic delivery of naked plasmid DNA facilitated by pCytomegalovirus-Sleep Beauty (pCMV-SB) transposons was technically feasible and devoid of cardiovascular and local adverse events in all 12 pigs. Furthermore, plasmid DNA (both single and combination) was successfully transferred into swine hepatocytes in all 12 pigs. Additionally, stable integration of the DNA constructs in hepatocyte genomic DNA was reliably noted at all 3 time points. In the 4 swine that were kept alive to 60 days, successful genomic integration and subsequent protein expression was observed in the targeted liver tissue.

CONCLUSIONS

ERCP-guided hydrodynamic delivery of gene therapy may usher in the next chapter in gene therapy with the potential to impact a variety of single-gene, complex genetic, and epigenetic liver diseases. It also raises the possibility that other nucleic acid therapeutics (microRNA, lncRNA, siRNA, shRNA) could similarly be delivered.

Exosome miR-335 as a novel therapeutic strategy in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common and deadly cancer. Most cases of HCC arise in a cirrhotic/fibrotic liver, indicating that environment may play a paramount role in cancer genesis. Previous studies from our group and others have shown that, in desmoplastic cancers, there is a rich intercellular communication between activated, cancer-associated fibroblasts and cancer cells. Moreover, extracellular vesicles (EVs), or exosomes, have been identified as an important arm of this intercellular communication platform. Finally, these studies have shown that EVs can carry microRNA (miR) species in vivo and deliver them to desmoplastic cancers. The precise role played by activated liver fibroblasts/stellate cells in HCC development is insufficiently known. Based on previous studies, it appears plausible that activated fibroblasts produce signals carried by EVs that promote HCC genesis. In the current study, we first hypothesized and then demonstrated that stellate cell-derived EVs 1) can be loaded with an miR species of choice (miR-335-5p); 2) are taken up by HCC cells in vitro and more importantly in vivo; 3) can supply the miR-335-5p cargo to recipient HCC cells in vitro as well as in vivo; and 4) inhibit HCC cell proliferation and invasion in vitro as well as induce HCC tumor shrinkage in vivo. Finally, we identified messenger RNA targets for miR-335 that are down-regulated after treatment with EV-miR-335-5p. This study informs potential therapeutic strategies in HCC, whereby stellate cell-derived EVs are loaded with therapeutic nucleic acids and delivered in vivo. (Hepatology 2018;67:940-954).

Stimuli-Responsive Soft Untethered Grippers for Drug Delivery and Robotic Surgery

Untethered microtools that can be precisely navigated into deep in vivo locations are important for clinical procedures pertinent to minimally invasive surgery and targeted drug delivery. In this mini-review, untethered soft grippers are discussed, with an emphasis on a class of autonomous stimuli-responsive gripping soft tools that can be used to excise tissues and release drugs in a controlled manner. The grippers are composed of polymers and hydrogels and are thus compliant to soft tissues. They can be navigated using magnetic fields and controlled by robotic path-planning strategies to carry out tasks like pick-and-place of microspheres and biological materials either with user assistance, or in a fully autonomous manner. It is envisioned that the use of these untethered soft grippers will translate from laboratory experiments to clinical scenarios and the challenges that need to be overcome to make this transition are discussed.

Extracellular vesicles carry microRNA-195 to intrahepatic cholangiocarcinoma and improve survival in a rat model

The cancer microenvironment plays a central role in cancer development, growth, and homeostasis. This paradigm suggests that cancer fibroblasts support cancers, probably in response to stimuli received from the cancer cells. We aimed at investigating whether extracellular vesicles (EVs) can shuttle microRNA (miR) species between cancer-associated fibroblasts (CAFs) and cancer cells. To this end, we extracted EVs according to published protocols. EVs were studied for their miR content by quantitative reverse-transcription polymerase chain reaction. EVs were transfected with select miR species and utilized in vitro as well as in vivo in a rat model of cholangiocarcinoma (CCA). We found that miR-195 is down-regulated in CCA cells, as well as in adjoining fibroblasts. Furthermore, we report that EVs shuttle miR-195 from fibroblasts to cancer cells. Last, we show that fibroblast-derived EVs, loaded with miR-195, can be administered in a rat model of CCA, concentrate within the tumor, decrease the size of cancers, and improve survival of treated rats.

CONCLUSION

EVs play a salient role in trafficking miR species between cancer cells and CAFs in human CCA. Understanding of these mechanisms may allow devising of novel therapeutics. (Hepatology 2017;65:501-514).

Isolation and Profiling of MicroRNA-containing Exosomes from Human Bile

Exosome research in the last three years has greatly extended the scope towards identification and characterization of biomarkers and their therapeutic uses. Exosomes have recently been shown to contain microRNAs (miRs). MiRs themselves have arisen as valuable biomarkers for diagnostic purposes. As specimen collection in clinics and hospitals is quite variable, miRNA isolation from whole bile varies substantially. To achieve robust, accurate and reproducible miRNA profiles from collected bile samples in a simple manner required the development of a high-quality protocol to isolate and characterize exosomes from bile. The method requires several centrifugations and a filtration step with a final ultracentrifugation step to pellet the isolated exosomes. Electron microscopy, Western blots, flow cytometry and multi-parameter nanoparticle optical analysis, where available, are crucial characterization steps to validate the quality of the exosomes. For the isolation of miRNA from these exosomes, spiking the lysate with a non-specific, synthetic miRNA from a species like Caenorhabditis elegans, i.e., Cel-miR-39, is important for normalization of RNA extraction efficiency. The isolation of exosome from bile fluid following this method allows the successful miRNA profiling from bile samples stored for several years at -80 °C.

Whole-Exome Sequencing Analyses of Inflammatory Bowel Disease-Associated Colorectal Cancers

BACKGROUND & AIMS

A long duration of inflammatory bowel disease (IBD) increases the risk for colorectal cancer. Mutation analysis of limited numbers of genes has indicated that colorectal tumors that develop in patients with IBD differ from those of patients without IBD. We performed whole-exome sequencing analyses to characterize the genetic landscape of these tumors.

METHODS

We collected colorectal tumor and non-neoplastic tissues from 31 patients with IBD and colorectal cancer (15 with ulcerative colitis, 14 with Crohn's disease, and 2 with indeterminate colitis) and performed whole-exome sequencing analyses of the microdissected tumor and matched nontumor tissues. We identified somatic alterations by comparing matched specimens. The prevalence of mutations in sporadic colorectal tumors was obtained from previously published exome-sequencing studies.

RESULTS

Two specimens had somatic mutations in the DNA proofreading or mismatch repair genes POLE, MLH1, and MSH6 and the tumor cells had a hypermutable phenotype. The remaining tumors had, on average, 71 alterations per sample. TP53 was the most commonly mutated gene, with prevalence similar to that of sporadic colorectal tumors (63% of cases). However, tumors from the patients with IBD had a different mutation spectrum. APC and KRAS were mutated at significantly lower rates in tumors from patients with IBD than in sporadic colorectal tumors (13% and 20% of cases, respectively). Several genes were mutated more frequently or uniquely in tumors from patients with IBD, including SOX9 and EP300 (which encode proteins in the WNT pathway), NRG1 (which encodes an ERBB ligand), and IL16 (which encodes a cytokine). Our study also revealed recurrent mutations in components of the Rho and Rac GTPase network, indicating a role for noncanonical WNT signaling in development of colorectal tumors in patients with IBD.

CONCLUSIONS

Colorectal tumors that develop in patients with IBD have distinct genetic features from sporadic colorectal tumors. These findings could be used to develop disease-specific markers for diagnosis and treatment of patients with IBD and colorectal cancer.

Pseudogene INTS6P1 regulates its cognate gene INTS6 through competitive binding of miR-17-5p in hepatocellular carcinoma

The complex regulation of tumor suppressive gene and its pseudogenes play key roles in the pathogenesis of hepatocellular cancer (HCC). However, the roles played by pseudogenes in the pathogenesis of HCC are still incompletely elucidated. This study identifies the putative tumor suppressor INTS6 and its pseudogene INTS6P1 in HCC through the whole genome microarray expression. Furthermore, the functional studies – include growth curves, cell death, migration assays and in vivo studies – verify the tumor suppressive roles of INTS6 and INTS6P1 in HCC. Finally, the mechanistic experiments indicate that INTS6 and INTS6P1 are reciprocally regulated through competition for oncomiR-17-5p. Taken together, these findings demonstrate INTS6P1 and INTS6 exert the tumor suppressive roles through competing for oncomiR-17-5p. Our investigation of this regulatory circuit reveals novel insights into the underlying mechanisms of hepatocarcinogenesis.

MicroRNA-224 Induces G1/S Checkpoint Release in Liver Cancer

Profound changes in microRNA (miR) expression levels are frequently found in liver cancers compared to the normal liver. In this study, we evaluate the expression of miR-224 in human HCC and CCA, as well as its downstream targets and affected pathways. We show that miR-224 is upregulated in a large cohort of human CCA, similar to its upregulation in human HCC. For the purpose of studying the roles of miR-224 in HCC and CCA, we enforced miR-224 expression in cells. mRNA arrays followed by Ingenuity Pathway Analysis (IPA)-identified putative molecules and pathways downstream of miR-224. Phenotypically, we report that enforced expression of miR-224 increases the growth rate of normal cholangiocytes, CCA cell lines, and HCC cell lines. In addition, we identified, in an unbiased fashion, that one of the major biologic processes affected by miR-224 is Gap1 (G1) to Synthesis (S) transition checkpoint release. We next identified p21, p15, and CCNE1 as downstream targets of miR-224 and confirmed the coordinated downregulation results in the increased phosphorylation of Retinoblastoma (Rb) with resulting G1/S checkpoint release. Our data suggest that miR-224 is a master regulator of cell cycle progression, and that its overexpression results in G1/S checkpoint release followed by accelerated cell growth.

MicroRNAs in the biology and diagnosis of cholangiocarcinoma

Ever since their discovery, microRNAs (miRNAs) have been the subject of intense investigation of their roles in cells and tissues, both normal and disease state. Although some of the precise mechanisms of biogenesis and actions of miRNAs remain debatable, the fact that miRNAs are dysregulated in diseases such as cancer is undisputed. For many miRNA species, computational databases predict often numerous targets; however, experimental verification in vitro and in vivo is still lacking. For some miRNAs, species-specific targets have been validated; nevertheless, the precise mechanisms those targets act in and whether they are the only truly important ones remain to be discovered. The authors take a closer look at the current status of the role of miRNAs in the diagnosis and biology of cholangiocarcinomas where the perhaps biggest impact in the short term comes from the use of biomarkers in the early diagnosis.

Human bile contains microRNA-laden extracellular vesicles that can be used for cholangiocarcinoma diagnosis

Cholangiocarcinoma (CCA) presents significant diagnostic challenges, resulting in late patient diagnosis and poor survival rates. Primary sclerosing cholangitis (PSC) patients pose a particularly difficult clinical dilemma because they harbor chronic biliary strictures that are difficult to distinguish from CCA. MicroRNAs (miRs) have recently emerged as a valuable class of diagnostic markers; however, thus far, neither extracellular vesicles (EVs) nor miRs within EVs have been investigated in human bile. We aimed to comprehensively characterize human biliary EVs, including their miR content. We have established the presence of extracellular vesicles in human bile. In addition, we have demonstrated that human biliary EVs contain abundant miR species, which are stable and therefore amenable to the development of disease marker panels. Furthermore, we have characterized the protein content, size, numbers, and size distribution of human biliary EVs. Utilizing multivariate organization of combinatorial alterations (MOCA), we defined a novel biliary vesicle miR-based panel for CCA diagnosis that demonstrated a sensitivity of 67% and specificity of 96%. Importantly, our control group contained 13 PSC patients, 16 with biliary obstruction of varying etiologies (including benign biliary stricture, papillary stenosis, choledocholithiasis, extrinsic compression from pancreatic cysts, and cholangitis), and 3 with bile leak syndromes. Clinically, these types of patients present with a biliary obstructive clinical picture that could be confused with CCA.

CONCLUSION

These findings establish the importance of using extracellular vesicles, rather than whole bile, for developing miR-based disease markers in bile. Finally, we report on the development of a novel bile-based CCA diagnostic panel that is stable, reproducible, and has potential clinical utility.

Stimuli-responsive theragrippers for chemomechanical controlled release

We report on a therapeutic approach using thermo-responsive multi-fingered drug eluting devices. These therapeutic grippers referred to as theragrippers are shaped using photolithographic patterning and are composed of rigid poly(propylene fumarate) segments and stimuli-responsive poly(N-isopropylacrylamide-co-acrylic acid) hinges. They close above 32 °C allowing them to spontaneously grip onto tissue when introduced from a cold state into the body. Due to porosity in the grippers, theragrippers could also be loaded with fluorescent dyes and commercial drugs such as mesalamine and doxorubicin, which eluted from the grippers for up to seven days with first order release kinetics. In an in vitro model, theragrippers enhanced delivery of doxorubicin as compared to a control patch. We also released theragrippers into a live pig and visualized release of dye in the stomach. The design of such tissue gripping drug delivery devices offers an effective strategy for sustained release of drugs with immediate applicability in the gastrointestinal tract.

Exome sequencing identifies frequent inactivating mutations in BAP1, ARID1A and PBRM1 in intrahepatic cholangiocarcinomas

Through exomic sequencing of 32 intrahepatic cholangiocarcinomas, we discovered frequent inactivating mutations in multiple chromatin-remodeling genes (including BAP1, ARID1A and PBRM1), and mutation in one of these genes occurred in almost half of the carcinomas sequenced. We also identified frequent mutations at previously reported hotspots in the IDH1 and IDH2 genes encoding metabolic enzymes in intrahepatic cholangiocarcinomas. In contrast, TP53 was the most frequently altered gene in a series of nine gallbladder carcinomas. These discoveries highlight the key role of dysregulated chromatin remodeling in intrahepatic cholangiocarcinomas.

Biopsy with thermally-responsive untethered microtools

Thermally activated, untethered microgrippers can reach narrow conduits in the body and be used to excise tissue for diagnostic analyses. As depicted in the figure, the feasibility of an in vivo biopsy of the porcine bile duct using untethered microgrippers is demonstrated.

miRNA-Based Therapeutic Strategies

Micro-RNAs (miRNAs) are short non-coding RNA species, thought to act primarily through downregulation of target mRNA species with subsequent decrease in encoded proteins. Recent studies revealed that miRNAs play pivotal roles in physiology and disease, and therapeutic targeting has started being investigated. Generally, the up-regulation of miRNAs is achieved through administration of synthetic miRNAs or administration of miRNA expressing vectors. The down-regulation of miRNAs is achieved through administration of anti-sense nucleotides, often chemically modified to ensure stability and specificity. There are multiple potential limitations associated with the development and testing of miRNAs-based therapeutics. These issues include, but are not limited to, off-target effect, avoidance from internal nucleases, and toxicity for miRNA therapy. In this review, we will discuss recent advances in miRNA based therapeutic strategies.

Coordinated effects of microRNA-494 induce G₂/M arrest in human cholangiocarcinoma

MicroRNA (miRs) have emerged as salient regulators in cancer homeostasis and, recently, as putative therapeutics. Cholangiocarcinomas (CCA) are aggressive cancers with survival usually measured in months. mRNA arrays followed by pathway analysis revealed that miR-494 is a major modulator of the cell cycle progression from gap 2 (G₂) to mitosis (M). We performed fluorescence activated cell sorting (FACS) as well as differential interference contrast (DIC) microscopy, and confirmed that miR-494 induces a significant arrest in G₂/M in CCA cells. Furthermore, we verified that miR-494 modulates the protein level of six genes involved in the G₂/M transition: Polo-like Kinase 1 (PLK1), pituitary tumor-transforming gene 1 (PTTG1), Cyclin B1 (CCNB1), cell-division cycle 2 (CDC2), cell-division cycle 20 (CDC20) and topoisomerase II α (TOP2A). Next, we identified direct binding of miR-494 to the open reading frame (ORF) and downregulation of PTTG1 and TOP2A. In summary, our findings suggest that miR-494 has a global regulatory role in cell cycle progression, exerted by concerted effects on multiple proteins involved in gap 1 (G₁) to synthesis (S), as described previously, as well as G₂ to M progression. Therefore, it appears that the simultaneous effects of a single miR species on multiple targets along the same canonical pathway is advantageous for the usage of miRs as therapeutics. In addition, our data suggest that miRs act within a narrow range. miR expression above the upper threshold does not appear to induce further effects, which is reassuring in terms of off-target effects of miR surrounding noncancerous tissue.

MicroRNA-21 inhibits Serpini1, a gene with novel tumour suppressive effects in gastric cancer

BACKGROUND

A thorough understanding of gastric cancer at the molecular level is urgently needed. One prominent oncogenic microRNA, miR-21, was previously reported to be upregulated in gastric cancer.

METHODS

We performed an unbiased search for downstream messenger RNA targets of miR-21, based on miR-21 dysregulation, by using human tissue specimens and the MKN28 human gastric carcinoma cell line. Molecular techniques include microRNA microarrays, cDNA microarrays, qRT-PCR for miR and mRNA expression, transfection of MKN28 with miR-21 inhibitor or Serpini1 followed by Western blotting, cell cycle analysis by flow cytometry and luciferase reporter assay.

RESULTS

This search identified Serpini1 as a putative miR-21 target. Luciferase assays demonstrated direct interaction between miR-21 and Serpini1 3'UTR. miR-21 and Serpini1 expression levels were inversely correlated in a subgroup of gastric cancers, suggesting a regulatory mechanism that included both of these molecules. Furthermore, Serpini1 induced growth retardation of MKN28 and induced vigorous G1/S arrest suggesting its potential tumour-suppressive function in the stomach.

CONCLUSION

Taken together, these data suggest that in a subgroup of gastric cancers, miR-21 is upregulated, inducing downregulation of Serpini1, which in turn releases the G1-S transition checkpoint, with the end result being increased tumour growth.

MicroRNA down-regulated in human cholangiocarcinoma control cell cycle through multiple targets involved in the G1/S checkpoint

MicroRNAs (miRs) recently emerged as prominent regulators of cancer processes. In the current study we aimed at elucidating regulatory pathways and mechanisms through which miR-494, one of the miR species found to be down-regulated in cholangiocarcinoma (CCA), participates in cancer homeostasis. miR-494 was identified as down-regulated in CCA based on miR arrays. Its expression was verified with quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR). To enforce miR expression, we employed both transfection methods, as well as a retroviral construct to stably overexpress miR-494. Up-regulation of miR-494 in cancer cells decreased growth, consistent with a functional role. mRNA arrays of cells treated with miR-494, followed by pathway analysis, suggested that miR-494 impacts cell cycle regulation. Cell cycle analyses demonstrated that miR-494 induces a significant G1/S checkpoint reinforcement. Further analyses demonstrated that miR-494 down-regulates multiple molecules involved in this transition checkpoint. Luciferase reporter assays demonstrated a direct interaction between miR-494 and the 3'-untranslated region of cyclin-dependent kinase 6 (CDK6). Last, xenograft experiments demonstrated that miR-494 induces a significant cancer growth retardation in vivo.

CONCLUSION

Our findings demonstrate that miR-494 is down-regulated in CCA and that its up-regulation induces cancer cell growth retardation through multiple targets involved in the G1-S transition. These findings support the paradigm that miRs are salient cellular signaling pathway modulators, and thus represent attractive therapeutic targets. miR-494 emerges as an important regulator of CCA growth and its further study may lead to the development of novel therapeutics.