Search Results (222)

Background: The potential of injectable hydrogels as drug depots lies in their ability to achieve local and sustained co-delivery of chemotherapeutic drugs and immunostimulants for combined tumor therapy. Method: In this study, we devised a localized chemo-immunotherapeutic strategy by co-loading the chemotherapeutic drug, oxaliplatin (OXA), and the immune-checkpoint blockade (ICB) antibody, anti-programmed cell death protein ligand 1 (anti-PD-L1), into a matrix metalloproteinase (MMP)-responsive injectable poly(L-glutamic acid) hydrogel (MMP-gel). Results: The in situ gelation of hydrogels enables local retention of OXA and model antibody IgG, as well as MMP-triggered sustained release. Meanwhile, the OXA-loaded MMP-gel caused the immunogenic cell death (ICD) of tumor cells. When administered intratumorally in mice carrying B16F10 melanoma, the MMP-gel co-loaded with OXA and anti-PD-L1 (OXA&anti-PD-L1@MMP-gel) demonstrated superior tumor suppression efficacy and prolonged the survival time of the animals with low systemic toxicity. Meanwhile, the OXA&anti-PD-L1@MMP-gel induced an increase in CD8⁺ T cells and M1 macrophages within tumors, and a decrease in Treg cells and M2 macrophages, demonstrating that the drug-loaded system enhanced the antitumor immune response. Moreover, the OXA&anti-PD-L1@MMP-gel effectively inhibited the growth of distal tumors in a bilateral-tumor experiment. Conclusions: Consequently, the responsive hydrogel-based chemo-immunotherapy holds potential in tumor treatment. Full article

Liposomes modified with slightly acidic pH-sensitive peptides (SAPSp-lipo) are effectively delivered to tumor tissues, followed by cellular uptake in the tumor microenvironment. Although SAPSp-lipo can penetrate tumor tissues via the interspace route between cancer cells and the extracellular matrix (ECM), penetration needs to be enhanced to deliver liposomes into tumor cores comprising malignant cancer cells. To enhance the intratumoral penetration of SAPSp-lipo, we focused on the internalizing RGD peptide (iRGD), which can penetrate tumor tissue, differing from the penetration mechanism of SAPSp. In this study, we developed liposomes modified with iRGD-conjugated SAPSp (SAPSp-iRGD-lipo). Compared with SAPSp-lipo, SAPSp-iRGD-lipo was delivered to deeper regions within both spheroids and tumor tissues. The enhanced penetration was suppressed by a co-treatment with a Neuropilin-1 inhibitor, and the fluorescence signals from intratumorally injected SAPSp-iRGD-lipo were localized in Neuropilin-1-expressing regions, indicating a Neuropilin-1-mediated tumor penetration. Moreover, SAPSp-iRGD-lipo reduced F-actin formation in monolayered cells and was not localized in F-actin-rich regions in tumors, suggesting that SAPSp-iRGD-lipo facilitates tumor penetration through actin depolymerization. In addition, anticancer siRNA delivered by SAPSp-iRGD-lipid nanoparticles effectively induced apoptosis in cells under slightly acidic conditions. Taken together, SAPSp-iRGD-modified nanoparticles represent a novel class of tumor-penetrable and microenvironment-responsive drug carriers capable of efficient intratumoral delivery and therapeutic activity. Full article

Objectives: This paper reports the preclinical evaluation of stable tumor-specific gold nanoparticles (AuNPs) activated by neutron irradiation as a therapeutic option for the treatment of cancers characterized by high tumor angiogenesis. Methods: A selection of promising AuNPs with high avidity to α_vβ₃-expressing glioma (U-87 MG) cells (IC₅₀ = 82–104 nM) were chosen with different surface loading of Arg-Gly-Asp (RGD) peptides as tumor targeting vectors for integrin α_vβ₃, a target which is overexpressed in tissues displaying high tumor angiogenesis. Three different [¹⁹⁸Au]AuNPs were evaluated applying three injection methods, intravenous (i.v.), intraperitoneal (i.p.), and intratumoral (i.t.), each in a group of six U-87 MG xenograft–bearing mice (54 female athymic nude mice in total). Their biodistribution and tumor accumulation was assessed by in vivo imaging within 1–7 days after injection and 7 days after injection by ex vivo measurement. Results: The developed [¹⁹⁸Au]AuNPs exhibited suboptimal biodistribution by i.v. application (accumulation pattern tail > liver > spleen, no significant tumor accumulation) and by i.p. application (accumulation pattern spleen >> liver > pancreas, slight tumor accumulation of <0.3 %ID/g). However, an acceptable biodistribution by i.t. application was observed (5.5 %ID/g in liver, 4.9 %ID/g in spleen, and 3.0 %ID/g in tumor). Conclusions: Despite the very promising in vitro results, the in vivo evaluation suggests that the [¹⁹⁸Au]AuNPs represent a platform for the development of restricted therapeutic strategies. Full article

In the past decade, research on recombinant oncolytic viral agents in the treatment of solid tumors has evolved from the initial stage of simple genetic engineering to the current stage of multiple pipelines of parallel clinical application and combination therapy. Compared with T-VEC, the classical therapeutic agent that only expresses GM-CSF, which was approved in 2015, most new oncolytic virus designs include diverse gene constructs to reduce toxic effects, enhance multiple antitumor immunity, avoid immune clearance, or enhance tumor targeting. The single route of administration that activates the inflammatory tumor immune microenvironment by intratumoral injection is no longer sufficient to meet the treatment needs of refractory solid tumors. In this review, we illustrated the construction patterns of typical recombinant oncolytic viral agents and their latest clinical trial progress. Secondly, we summarized the underlying mechanisms of the combined application of antiviral and antitumor immunity in the field of solid tumor immunotherapy. Finally, we explored the feasibility of the intravenous application of oncolytic viruses and their future development directions. We believe that the diversified treatment design of oncolytic viruses will bring more surprises to the immunotherapy of refractory tumors. Full article

Virotherapy is a promising method for treating oncological diseases, including such aggressive and difficult-to-treat brain tumors such as glioblastoma. Recombinant vaccinia virus VV-GMCSF-Lact has previously shown high antitumor potential against tumor cells of varying histogenesis, including gliomas, and completed a Phase I clinical trial, demonstrating safety and good tolerability in patients with recurrent/refractory metastatic breast cancer. Investigating two types of VV-GMCSF-Lact delivery, intravenous and intratumoral, into orthotopically transplanted C6 glioma in rats, it was shown that intratumoral injection significantly increases tumor volumes in comparison with intravenous virus delivery and is accompanied by noticeable toxic effects. Extensive areas of necrotic decay of tumor tissue and its significant mixed-cell infiltration and peritumoral edema, affecting the tumor volume, were detected using H&E staining of C6 tumors after intratumoral injection of VV-GMCSF-Lact. However, only with intratumoral administration was a significant decrease in the level of the tumor cell proliferation marker Ki67 demonstrated by immunohistochemical staining. The observed toxic effects of VV-GMCSF-Lact with intratumoral administration revealed the need for dose selection, which was performed on a mouse GL261 glioma model. Results of the study allowed us to determine the viral dose that does not lead to toxic effects and can potentially increase life expectancy of mice. The data obtained show the need for careful selection of both the route of viral drug dose and administration. Full article

Background/Objectives: Little is known about the synergy between intratumoral immunotherapy and cancer ablation. We conducted a Phase II Trial (Abscopal 5001 trial; NCT04713371) in patients with metastatic solid cancer to assess the safety and efficacy of cryoablation with concurrent injection of RPT-01-5001 (combination of low-dose checkpoint inhibitors and cyclophosphamide), a treatment process referred to as Multiplex Intratumoral Immunotherapy (MITI^TM). Methods: Twelve patients with metastatic cancer who had failed standard therapy and one with sacral chordoma received at least one intratumoral treatment of MITI preceded by 3–5 days of oral low-dose cyclophosphamide. MITI consisted of CT-guided cryoablation followed by intratumoral injection of RPT-01-5001. GM-CSF was subcutaneously administered daily for four weeks. Treatment was repeated every four weeks if the tumor burden remained stable or reduced, as noted by the iRECIST criteria. These criteria were modified when follow-up biopsies revealed pathology with minimal or no cancer, despite persistent suspicious masses on imaging. Results: Cancers included prostate (four patients), sarcoma (two), and one each of breast, colon, bladder, uterine cervix, tongue, kidney, and sacral chordoma. Eight patients received three cycles of treatment, two received two, and three received one. All patients tolerated the procedure well and were discharged within 2 h. The adverse event rate was 69%, all of which were grade 1 or 2, except for two grade 3 cases with delayed cryosurgical complications (15%). At completion of up to three cycles of treatment, a complete response (iCR) was observed in one patient (7.7%), partial response (iPR) in four patients (30.8%), and stable disease (iSD) in five (38.5%), with a disease control rate (iDCR) of 77%. Disparity between post-treatment imaging and pathologic findings was observed in four patients (positive vs. negative, respectively), requiring modification of the iRECIST criteria in favor of pathology. The best response ranged from 0 to 91%, with a mean for responding patients of 38%. Median progression-free survival (PFS) and 95% confidence intervals (95% CI) were 5.4 months (1.8 to 23.1 months); and median overall survival (OS) was 20.9 months (9.1 to 22.8 months). The injection site cancer response was observed in nine (69%) patients, and the distal abscopal effect was seen in four (31%), including one sarcoma patient with a complete abscopal response of lung metastases and one bladder cancer patient with biopsy-confirmed complete resolution of lung and liver metastases. Conclusions: MITI with RPT-01-5001 is safe and highly feasible, providing 77% disease control and 31% of the abscopal effect in patients with metastatic cancer who have failed standard therapies. Full article

Recent evidence highlights the role of extrachromosomal circular DNAs (eccDNAs) in cancers. However, reports regarding its role in hepatocellular carcinoma (HCC) are infrequent. The abundance of eccDNAs from five HCC/adjacent tissue pairs was explored using Circle-Sequencing. eccDNA PAFAH1B3 was selected as one of the objects. The effect of eccDNA PAFAH1B3 on HCC progression was determined using EdU, Transwell, and apoptosis assays. Additionally, the expressions of eccDNA PAFAH1B3, mRNA PAFAH1B3, and epithelial–mesenchymal transition (EMT)-related markers were determined using RT-PCR and WB. A xenograft tumor model was established to explore the function of PAFAH1B3 in vivo, and EMT-related markers were detected using RT-PCR and IHC analyses. The abundance of eccDNA PAFAH1B3 was significantly increased in HCC cell lines after transfection with eccDNA PAFAH1B3, and promoted the proliferation, migration, and invasion of liver cells while inhibiting apoptosis. The levels of mRNA PAFAH1B3 were also upregulated. Furthermore, intratumoral injection of PAFAH1B3 inhibitor suppressed tumor growth, and PAFAH1B3 knockdown increased and decreased the levels of the E-cadherin and N-cadherin, respectively. Our study findings reveal that eccDNA PAFAH1B3 may promote the occurrence and development of HCC by enhancing the expression of PAFAH1B3 and regulating EMT. Full article

The unique ability of oncolytic viruses (OVs) to replicate in and destroy malignant cells while leaving healthy cells intact and activating the host immune response makes them powerful targeted anti-cancer therapeutic agents. Vesicular stomatitis virus (VSV) only causes mild and asymptomatic infection, lacks pre-existing immunity, can be genetically engineered for enhanced efficiency and improved safety, and has a broad cell tropism. VSV can facilitate targeted delivery of immunostimulatory cytokines for an enhanced immune response against cancer cells, thus decreasing the possible toxicity frequently observed as a result of systemic delivery. In this study, the oncolytic potency of the two rVSV versions, rVSV-dM51-GFP, delivering green fluorescent protein (GFP), and rVSV-dM51-mIL12-mGMCSF, delivering mouse interleukin-12 (mIL-12) and granulocyte-macrophage colony-stimulating factor (mGMCSF), was compared on the four murine cancer cell lines of different origin and healthy mesenchymal stem cells (MSCs) at 24 h post-infection by flow cytometry. Lewis lung carcinoma (LL/2) cells were demonstrated to be more susceptible to the lytic effects of both rVSV versions compared to melanoma (B16-F10) cells. Detection of expression levels of antiviral and pro-apoptotic genes in response to the rVSV-dM51-GFP infection by quantitative PCR (qPCR) showed lower levels of IFIT, RIG-I, and N-cadherin and higher levels of IFNβ and p53 in LL/2 cells. Subsequently, C57BL/6 mice, infused subcutaneously with the LL/2 cells, were injected intratumorally with the rVSV-dM51-mIL12-mGMCSF 7 days later to assess the synergistic effect of rVSV and immunostimulatory factors. The in vivo study demonstrated that treatment with two rVSV-dM51-mIL12-mGMCSF doses 3 days apart resulted in a tumor growth inhibition index (TGII) of over 50%. Full article

Background/Objectives: Lung squamous cell carcinoma (SCC), a major subtype of non-small cell lung cancer, remains a significant clinical challenge due to a scarcity of actionable molecular targets and the limited effectiveness of current targeted therapies. Emerging treatment strategies inhibit the gene expression of lineage survival oncogenes such as ΔNp63 and SOX2. CRISPR interference (CRISPRi) is a promising method to downregulate these genes; however, the efficacy depends on effective delivery. Here, we focused on the delivery system using nanobubbles (NBs) and ultrasound (US) for site-specific CRISPRi delivery to SCC. We evaluated the therapeutic efficacy of plasmid-based CRISPRi (pCRISPRi) targeting SOX2 or ΔNp63 using intratumoral pCRISPRi/NBs injections followed by US. Methods: A mixture of NBs and pCRISPRi was injected directly into the tumors and exposed to US-induced cavitation to facilitate pCRISPRi uptake. Tumor volume was measured every other day, and apoptosis was assessed by TUNEL assay. Results: In a lung SCC xenograft model, NBs/US-mediated pCRISPRi delivery induced apoptosis and significantly suppressed tumor growth. Conclusions: These findings suggest that US-guided, NB-facilitated delivery of pCRISPRi can locally suppress lineage survival oncogenes and trigger tumor cell death, representing a promising targeted therapy for lung SCC. Additionally, this platform could be adapted to other cancers by targeting alternative factors. Full article

Intratumoral injections of macromolecules, such as biologics and immunotherapeutics, show promise in overcoming dose-limiting side effects associated with systemic injections and improve treatment efficacy. However, the retention of injectates in the tumor microenvironment is a major underappreciated challenge. High interstitial pressures and dense tumor architectures create shear forces that rapidly expel low-viscosity solutions post-injection. Injectable hydrogels may address these concerns by providing a viscoelastic delivery vehicle that shields loaded therapies from rapid expulsion from the tumor. A chitosan–glycerol hydrogel was thus developed and characterized with the goal of improving the injection retention of loaded therapeutics. The gelation parameters and mechanical properties of the hydrogel were explored to reveal a shear-thinning gel that is injectable through a 27-gauge needle. Biocompatibility studies demonstrated that the chitosan–glycerol hydrogel was nontoxic. Retention studies revealed significant improvements in the retention of model therapeutics when formulated with the chitosan–glycerol hydrogel compared to less-viscous solutions. Finally, release studies showed that there was a sustained release of model therapeutics of various molecular sizes from the hydrogel. Overall, the chitosan–glycerol hydrogel demonstrated injectability, enhanced retention, biocompatibility, and sustained release of macromolecules, indicating its potential for future clinical use in intratumoral macromolecule delivery. Full article

The rapid development of therapies using oncolytic viruses (OVs) has highlighted their unique advantages, such as their selective replication in tumor cells and their activation of a specific systemic antitumor immune response. However, effectively delivering OVs to tumor sites, especially solid tumor sites, remains a critical challenge. Intratumoral injections face significant barriers in treating some malignant tumors in internal organs, while increasing preclinical data support the use of intravenous injections. Nevertheless, intravenously injected viral particles may be prematurely cleared by circulating antibodies or complements, resulting in a reduced virus dose effectively reaching the tumor site. Therefore, developing methods to shield viruses from the neutralizing environment of the bloodstream while heading toward tumor sites is a must. In this review, we discuss some of the most promising delivery methods for OVs currently under investigation. Full article

Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine cutaneous malignancy with high rates of recurrence and metastasis. The treatment of MCC has historically involved surgery, radiation, and chemotherapy; however, current clinical trials are investigating immunotherapies, intratumoral injections, and combination therapies to improve outcomes. This review explores the current trends in clinical trials for MCC, highlighting recent advances in management. Full article

Checkpoint inhibitor therapy revolutionized the treatment of patients with melanoma. However, in patients where melanoma exhibits resistance to checkpoint inhibitor therapy, the treatment options are limited. Oncolytic viruses are a unique form of immunotherapy that uses live viruses to infect and lyse tumor cells to release the elusive neoantigen picked up by the antigen-presenting cells, thus increasing the chances of an immune response against cancer. Coupled with checkpoint inhibitors, intratumoral injections of the oncolytic virus can help an enhanced immune response, especially in a tumor that displays resistance to checkpoint inhibitors. However, oncolytic viruses are not bereft of challenges and face several obstacles in the tumor microenvironment. From the historical use of wild viruses to the sophisticated use of genetically modified viruses in the current era, oncolytic virus therapy has evolved tremendously in the last two decades. Increasing the ability of the virus to select the malignant cells over the non-malignant ones, circumventing the antiviral immune response from the body, and enhancing the oncolytic properties of the viral platform by attaching various ligands are some of the several improvements made in the last three decades. In this manuscript, we trace the journey of the development of oncolytic virus therapy, especially in the context of melanoma. We review the clinical trials of talimogene laherparepvec in patients with melanoma. We also review the data available from the clinical trials of vusolimogene oderparepvec in patients with melanoma. Finally, we review the use of various oncolytic viruses and their challenges in clinical development. This manuscript aims to create a comprehensive literature review for clinicians to understand and implement oncolytic virus therapy in patients diagnosed with melanoma. Full article

The NK-92 cell line has become a very relevant tool for natural killer (NK) cell research, largely because it largely mirrors the characteristics of human blood-derived NK cells. It also has a doubling time of less than 30 h, making it possible to generate a significant number of cells in a relatively short time. Its safety as an anti-cancer cell therapy has been documented in over 200 cancer patients. Various genetically engineered variants have been generated that express a high-affinity Fc-receptor and various chimeric antigen receptors (CARs) and secrete immune-active cytokines. NK-92 cells expressing CARs for HER-2, PD-L1, and CD19 CAR are in advanced clinical trials in cancer patients. These cells also have cytotoxic activity against targets infected with bacteria, fungi, and viruses. More recently, the cellular lysate of NK-92 cells, generated by simple freeze/thaw, has shown anti-cancer potential when injected intra-tumor. Since a comprehensive review of NK-92 was recently published on the occasion of its 30-year “anniversary”, this review will focus on more recent research initiatives and results with the cell line. Full article

Cryoablation is a promising, cost-effective option to de-escalate surgical breast cancer morbidity, but presently is only suggested for breast cancers < 1.5 cm, in select candidates. Breast cancer cryoablation is not a reliably covered procedure by insurance and is mainly guided by ultrasound (US), using a single cryoprobe. Yet, cryoablation is an accepted treatment option for various malignancies, including those of the kidney, liver and lung, utilizing a predominantly CT-guided, multi-probe approach using crucial cytotoxic isotherms for thorough tumor coverage. Cryoablation thus continues to find new clinical utility and is rapidly advancing on multiple fronts, similar to immunotherapy. Clinical concerns of expanding cryoablation to breast tumors > 1.5 cm is more related to the greater risk of metastatic spread to local lymph nodes and beyond. Combined adjuvant treatment, such as radiation and/or chemotherapy, are currently used for regional and systemic breast cancer control, but have significant associated morbidities. US/CT-guided multi-probe large-volume breast cryoablation is presented as a thorough local control option for select patients. Intratumoral chemotherapy by direct tumor injection has been shown to be safe and is currently being tested with immunotherapy drugs and exhibits much lower morbidity. Cryoablation combined with intratumoral immunotherapy is presented to show robust systemic immune response and the potential to provide additional protection from regional and/or metastatic disease spread while de-escalating the morbidities from current adjuvant treatments for larger breast cancers. While further clinical trials are needed, it is essential to pursue safe and effective breast cancer treatments that offer the potential for cost-efficiency and therapeutic de-escalation across a wide spectrum of breast cancer cases. Full article