Cancer therapeutics are developed through extensive screening; however, many therapeutics evaluated with 2D in vitro cultures during pre-clinical trials suffer from lower efficacy in patients. Replicating the in vivo tumor microenvironment in vitro with three-dimensional (3D) porous scaffolds offers the possibility of generating more predictive pre-clinical models to enhance cancer treatment efficacy. We developed a chitosan and hyaluronic acid (HA) polyelectrolyte complex 3D porous scaffold and evaluated its physical properties. Chitosan-HA (C-HA) scaffolds had a highly porous network. C-HA scaffolds were compared to 2D surfaces for in vitro culture of U-118 MG human glioblastoma (GBM) cells. C-HA scaffold cultures promoted tumor spheroid formation and increased stem-like properties of GBM cells as evidenced by the upregulation of CD44, Nestin, Musashi-1, GFAP, and HIF-1α as compared with 2D cultures. Additionally, the invasiveness of GBM cells cultured in C-HA scaffolds was significantly enhanced compared to those grown in 2D cultures. C-HA scaffold cultures were also more resistant to chemotherapy drugs, which corresponded to the increased expression of ABCG2 drug efflux transporter. These findings suggest that C-HA scaffolds offer promise as an in vitro GBM platform for study and screening of novel cancer therapeutics.

ObjectiveThe immune response to pancreatic ductal adenocarcinoma (PDA) may play a role in defining its uniquely aggressive biology; therefore, we sought to clearly define the adaptive immune infiltrate in PDA.DesignWe used immunohistochemistry and flow cytometry to characterize the immune infiltrate in human PDA and compared our findings to the patients’ peripheral blood.ResultsIn contrast to the myeloid cell predominant infiltrate seen in murine models, T cells comprised the majority of the hematopoietic cell component of the tumor stroma in human PDA. Most intratumoral CD8+ T cells exhibited an antigen-experienced effector memory cell phenotype and were capable of producing IFN-γ. CD4+ regulatory T cells (Treg) and IL-17 producing T helper cells were significantly more prevalent in tumor than in blood. Consistent with the association with reduced survival in previous studies, we observed higher frequencies of both myeloid cells and Treg in poorly differentiated tumors. The majority of intratumoral T cells expressed the co-inhibitory receptor programmed death-1 (PD-1), suggesting one potential mechanism through which PDA may evade antitumor immunity. Successful multimodal neoadjuvant therapy altered the immunoregulatory balance and was associated with reduced infiltration of both myeloid cells and Treg.ConclusionOur data show that human PDA contains a complex mixture of inflammatory and regulatory immune cells, and that neoadjuvant therapy attenuates the infiltration of intratumoral cells associated with immunosuppression and worsened survival.

Hepatocellular carcinoma (HCC) is a devastating malignancy in which imperfect imaging plays a primary role in diagnosis. Glypican-3 (GPC3) is an HCC-specific cell surface proteoglycan overexpressed in most HCCs. This paper presents the use of 89Zr-conjugated monoclonal antibody against GPC3 (89Zr-αGPC3) for intrahepatic tumor localization using PET. Methods Polymerase chain reaction confirmed relative GPC3 expression in cell lines. In vitro binding, in vivo biodistribution, and small-animal PET studies were performed on GPC3-expressing HepG2 and non–GPC3-expressing HLF and RH7777 cells and orthotopic xenografts. Results 89Zr-αGPC3 demonstrated antibody-dependent, antigen-specific tumor binding. HepG2 liver tumors exhibited high peak uptake (836.6 ± 86.6 percentage injected dose [%ID]/g) compared with background liver (27.5 ± 1.6 %ID/g). Tumor-to-liver contrast ratio was high and peaked at 32.5. The smallest HepG2 tumor (<1 mm) showed lower peak uptake (42.5 ± 6.4 %ID/g) and tumor-to-liver contrast (1.57) but was still clearly visible on PET. Day 7 tissue activity was still substantial in HepG2 tumors (466.4 ± 87.6 %ID/g) compared with control RH7777 tumors (3.9 ± 1.3 %ID/g, P < 0.01), indicating antigen specificity by 89Zr-αGPC3. HepG2 tumor treated with unlabeled αGPC3 or heat-denatured 89Zr-αGPC3 demonstrated tumor activity (2.1 %ID/g) comparable to that of control xenografts, confirming antibody dependency. Conclusion This study demonstrated the feasibility of using 89Zr-αGPC3 to image HCC in the liver, as well as the qualitative determination of GPC3 expression via small-animal PET. The ability to clarify the identity of small liver lesions with an HCC-specific PET probe would provide clinicians with vital information that could significantly alter patient management, warranting further investigation for clinical translation.

Robotic technology is being utilized in multiple hepatobiliary procedures, including hepatic resections. The benefits of minimally invasive surgical approaches have been well documented; however, there is some concern that robotic liver surgery may be prohibitively costly and therefore should be limited on this basis. A single-institution, retrospective cohort study was performed of robotic and open liver resections performed for benign and malignant pathologies. Clinical and cost outcomes were analyzed using adjusted generalized linear regression models. Clinical and cost data for 71 robotic (RH) and 88 open (OH) hepatectomies were analyzed. Operative time was significantly longer in the RH group (303 vs. 253 min; p = 0.004). Length of stay was more than 2 days shorter in the RH group (4.2 vs. 6.5 days; p < 0.001). RH perioperative costs were higher ($6026 vs. $5479; p = 0.047); however, postoperative costs were significantly lower, resulting in lower total hospital direct costs compared with OH controls ($14,754 vs. $18,998; p = 0.001). Robotic assistance is safe and effective while performing major and minor liver resections. Despite increased perioperative costs, overall RH direct costs are not greater than OH, the current standard of care.

Around the world, recommendations for cancer treatment are being adapted in real time in response to the pandemic of COVID-19. We, as a multidisciplinary team, reviewed the standard management options, according to the Barcelona Clinic Liver Cancer classification system, for hepatocellular carcinoma. We propose treatment recommendations related to COVID-19 for the different stages of hepatocellular carcinoma (ie, 0, A, B, and C), specifically in relation to surgery, locoregional therapies, and systemic therapy. We suggest potential strategies to modify risk during the pandemic and aid multidisciplinary treatment decision making. We also review the multidisciplinary management of intrahepatic cholangiocarcinoma as a potentially curable and incurable diagnosis in the setting of COVID-19.

Hepatocellular carcinoma (HCC) is an increasingly lethal malignancy for which management is critically dependent on accurate imaging. Glypican-3 (GPC3) is a cell surface receptor overexpressed in most HCCs and provides a unique target for molecular diagnostics. The use of monoclonal antibodies (mAbs) that target GPC3 (αGPC3) in PET imaging has shown promise but comes with inherent limitations associated with mAbs such as long circulation times. This study used 89Zr-conjugated F(ab′)2 fragments directed against GPC3 (89Zr-αGPC3-F(ab′)2) to evaluate the feasibility of the fragments as a diagnostic immuno-PET imaging probe. Methods Immobilized ficin was used to digest αGPC3, creating αGPC3-F(ab′)2 fragments subsequently conjugated to 89Zr. In vivo biodistribution and PET studies were performed on GPC3-expressing HepG2 and GPC3-nonexpressing RH7777 orthotopic xenografts. Results Reliable αGPC3-F(ab′)2 production via immobilized ficin digestion was verified by high-performance liquid chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis. 89Zr-αGPC3-F(ab′)2 demonstrated F(ab′)2-dependent, antigen-specific cell binding. HepG2 tumor uptake was higher than any other tissue, peaking at 100 ± 21 percentage injected dose per gram (%ID/g) 24 h after injection, a value 33- to 38-fold higher than GPC3-nonexpressing RH7777 tumors. The blood half-life of the 89Zr-αGPC3-F(ab′)2 conjugate was approximately 11 h, compared with approximately 115 h for historic mAb controls. This shorter half-life enabled clear tumor visualization on PET 4 h after administration, with a resultant peak tumor-to-liver contrast ratio of 23.3. Blocking antigen-expressing tumors with an excess of nonradiolabeled αGPC3 resulted in decreased tumor uptake similar to native liver. The kidneys exhibited high tissue uptake, peaking at 24 h with 83 ± 12 %ID/g. HepG2 tumors ranging from 1.5 to 7 mm were clearly visible on PET, whereas larger RH7777 tumors displayed signal lower than background liver tissue. Conclusion This study demonstrates the feasibility of using 89Zr-αGPC3-F(ab′) 2 for intrahepatic tumor localization with small-animal PET. Faster blood clearance and lower background liver uptake enable excellent signal-to-noise ratios at early time points. Increased renal uptake is similar to that as has been seen with clinical radioactive peptide imaging. 89Zr-αGPC3-F(ab′)2 addresses some of the shortcomings of whole-antibody immuno-PET probes. Further optimization is warranted to maximize probe sensitivity and specificity in the process of clinical translation.

Hepatocellular carcinoma (HCC) is one of the deadliest cancers worldwide. Small interfering RNA (siRNA) holds promise as a new class of therapeutics for HCC as it can achieve sequence-specific gene knockdown with low cytotoxicity. However, the main challenge in the clinical application of siRNA lies in the lack of effective delivery approaches that need to be highly specific and thus incur low or no systemic toxicity. Here, we present a non-viral nanoparticle-based gene carrier that can specifically deliver siRNA to HCC. The nanovector (NP-siRNA-GPC3 Ab) is made of an iron oxide core coated with chitosan-PEG grafted PEI copolymer, which is further functionalized with siRNA and conjugated with a monoclonal antibody (Ab) against human glypican-3 (GPC3) receptor highly expressed in HCC. A rat RH7777 HCC cell line that co-expresses human GPC3 and firefly luciferase (Luc) is established to evaluate the nanovector. The nanoparticle-mediated delivery of siRNA against Luc effectively suppresses Luc expression in vitro without notable cytotoxicity. Significantly, NP-siLuc-GPC3 Ab administered intravenously in an orthotopic model of HCC is able to specifically bound to tumor and induce remarkable inhibition of Luc expression. Our findings demonstrate the potential of using this nanovector for targeted delivery of therapeutic siRNA to HCC.

Medulloblastoma (MB) and ependymoma (EP) are the most common pediatric brain tumors, afflicting 3,000 children annually. Radiotherapy (RT) is an integral component in the treatment of these tumors; however, the improvement in survival is often accompanied by radiation-induced adverse developmental and psychosocial sequelae. Therefore, there is an urgent need to develop strategies that can increase the sensitivity of brain tumors cells to RT while sparing adjacent healthy brain tissue. Apurinic endonuclease 1 (Ape1), an enzyme in the base excision repair pathway, has been implicated in radiation resistance in cancer. Pharmacological and specificity limitations inherent to small molecule inhibitors of Ape1 have hindered their clinical development. Here we report on a nanoparticle (NP) based siRNA delivery vehicle for knocking down Ape1 expression and sensitizing pediatric brain tumor cells to RT. The NP comprises a superparamagnetic iron oxide core coated with a biocompatible, biodegradable coating of chitosan, polyethylene glycol (PEG), and polyethyleneimine (PEI) that is able to bind and protect siRNA from degradation and to deliver siRNA to the perinuclear region of target cells. NPs loaded with siRNA against Ape1 (NP:siApe1) knocked down Ape1 expression over 75% in MB and EP cells, and reduced Ape1 activity by 80%. This reduction in Ape1 activity correlated with increased DNA damage post-irradiation, which resulted in decreased cell survival in clonogenic assays. The sensitization was specific to therapies generating abasic lesions as evidenced by NP:siRNA not increasing sensitivity to paclitaxel, a microtubule disrupting agent. Our results indicate NP-mediated delivery of siApe1 is a promising strategy for circumventing pediatric brain tumor resistance to RT.