Lipophilic recombinant-protein insertion endows lymphocytes with enhanced targeting-infiltration ability in EGFR positive cancer.

Adoptive T cell transfer is one of the most promising ways to combat solid tumors. However, the weak infiltration of T cells into tumor sites has restricted their antitumor efficacy. To overcome this obstacle, we used the lipophilic protein painting strategy to improve tumor targeting and penetrating capacity of lymphocytes for the first time. We synthesized the lipid anchor consisting of a bispecific recombinant protein iRGD-antiEGFR and DSPE-PEG derivates, then successfully inserted it into the membranes of T cells. This surface modification was non-invasive and could efficiently improve the infiltration ability of T cells into multicellular spheroids and tumor masses. The surface modified T cells also displayed superior antitumor activities in EGFR-positive tumor xenografts via systematic infusion. Moreover, the permeability and antitumor efficacy of these surface painted T cells could be remarkably enhanced when used in combination with local low-dose irradiation.

Erythrocyte membrane nanoparticles improve the intestinal absorption of paclitaxel.

Paclitaxel (PTX) is a cytotoxic chemotherapy drug with encouraging activity in human malignancies. However, free PTX has a very low oral bioavailability due to its low aqueous solubility and the gastrointestinal drug barrier. In order to overcome this obstacle, we have designed erythrocyte membrane nanoparticles (EMNP) using sonication method. The permeability of PTX by EMNP was 3.5-fold (Papp = 0.425 nm/s) and 16.2-fold (Papp = 394.1 nm/s) higher than free PTX in MDCK-MDR1 cell monolayers and intestinal mucosal tissue, respectively. The in vivo pharmacokinetics indicated that the AUC0-t (µg/mL·h) and Cmax (µg/mL) of EMNP were 14.2-fold and 6.0-fold higher than that of free PTX, respectively. In summary, the EMNP appears to be a promising nanoformulation to enhance the oral bioavailability of insoluble and poorly permeable drugs.

[Evaluation for preparation and anticancer efficacy in vitro of drug-loaded nanoerythrosomes].

The objective of this study is to develop a new-type biodegradable, biocompatible curcumin-loaded nanoerythrosomes (Cur-RBC-NPs) by means of the sonication method. The size of Cur-RBC-NPs was optimized by varying drug loading parameters. The morphology, size distribution, stability, in vitro release pattern, cellular uptake of nanoparticles and in vitro anti-tumor effects were evaluated, respectively. The results showed the prepared Cur-RBC-NPs were nearly uniform spheres, with an average diameter of (245.7 ± 1.3) nm. Encapsulation efficiency (EE) and load efficiency (LE) of Cur-RBC-NPs were 50.65% ± 1.36% and 6.27% ± 0.29%. And the nanoparticles had a good sustained release property. According to the in vitro experiment, Cur-RBC-NPs were effectively taken in by tumor cells, and exhibited a significant anti-tumor effect. In conclusion, the method for preparing Cur-RBC-NPs is convenient, with a good sustained release behavior and anti-tumor efficacy, and so expected to be a new-type nano-drug delivery system in clinical practice.

Efficacy and safety of second-line therapy by S-1 combined with sintilimab and anlotinib in pancreatic cancer patients with liver metastasis: a single-arm, phase II clinical trial.

Background: Pancreatic adenocarcinoma carries a grim prognosis, and there are few recognized effective second-line treatment strategies. We attempted to evaluate the efficacy and safety of a combination of S-1, sintilimab, and anlotinib as a second-line treatment in pancreatic cancer patients with liver metastasis. Methods: Pancreatic cancer patients with liver metastases were recruited. S-1 was administered orally at 25 mg/m2 bid, anlotinib was administered orally at 12 mg qd from day 1 to day 14, and sintilimab was administered intravenously at 200 mg on day 1. This method was repeated every 21 days, and the therapeutic effect was evaluated every 3 cycles. The primary outcome was the objective response rate (ORR). Results: Overall, 23 patients were enrolled in this study of whom 19 patients had objective efficacy evaluation. The ORR was 10.5% (95% CI 0.4%-25.7%) in the evaluable population. The progression-free survival (PFS) was 3.53 (95% CI 2.50-7.50) months, and the overall survival (mOS) was 8.53 (95% CI 4.97-14.20) months. Grade 3 adverse events were 26.1%, and no grade 4 or above adverse events occurred. High-throughput sequencing was performed on the tumor tissues of 16 patients; patients with HRD-H (n = 10) had shorter PFS than those with HRD-L (n = 6) (2.43 vs. 5.45 months; P = 0.043), but there was no significant difference in OS between the two groups (4.43 vs. 9.35 months; P = 0.11). Conclusions: This study suggests the advantage of S-1 combined with sintilimab and anlotinib in extending OS as a second-line therapy in pancreatic cancer patients with liver metastasis. Clinical Trial Registration: ChiCTR2000030659.

First-line penpulimab (an anti-PD1 antibody) and anlotinib (an angiogenesis inhibitor) with nab-paclitaxel/gemcitabine (PAAG) in metastatic pancreatic cancer: a prospective, multicentre, biomolecular exploratory, phase II trial.

Metastatic pancreatic cancer (mPC) has a dismal prognosis. Herein, we conducted a prospective, multicentre, single-arm, phase II trial evaluating the efficacy and safety of penpulimab and anlotinib in combination with nab-paclitaxel/gemcitabine (PAAG) in patients with first-line mPC (NCT05493995). The primary endpoints included the objective response rate (ORR) and disease control rate (DCR), while secondary endpoints encompassed progression-free survival (PFS), overall survival (OS), and safety. In 66 patients analysed for efficacy, the best response, indicated by the ORR, was recorded at 50.0% (33/66) (95% CI, 37.4-62.6%), with 33 patients achieving partial response (PR). Notably, the DCR was 95.5% (63/66, 95% CI, 87.3-99.1%). The median PFS (mPFS) and OS (mOS) were 8.8 (95% CI, 8.1-11.6), and 13.7 (95% CI, 12.4 to not reached) months, respectively. Grade 3/4 treatment-related adverse events (TRAEs) were reported in 39.4% of patients (26/66). In prespecified exploratory analysis, patients with altered SWI/SNF complex had a poorer PFS. Additionally, low serum CA724 level, high T-cell recruitment, low Th17 cell recruitment, and high NK CD56dim cell scores at baseline were potential predicative biomarkers for more favourable efficacy. In conclusion, PAAG as a first-line therapy demonstrated tolerability with promising clinical efficacy for mPC. The biomolecular findings identified in this study possess the potential to guide the precise clinical application of the triple-combo regimen.

Single-arm study of camrelizumab plus apatinib for patients with advanced mucosal melanoma.

BACKGROUND: Previous studies have suggested the potential synergistic antitumor activity when combining immune checkpoint inhibitors with anti-angiogenic agents in various solid tumors. We aimed to assess the efficacy and safety of camrelizumab (a humanized programmed cell death-1 antibody) plus apatinib (a vascular endothelial growth factor receptor tyrosine kinase inhibitor) for patients with advanced mucosal melanoma (MM), and explore-related biomarkers. METHODS: We conducted a single-center, open-label, single-arm, phase II study. Patients with unresectable or recurrent/metastatic MM received camrelizumab and apatinib. The primary endpoint was the confirmed objective response rate (ORR). RESULTS: Between April 2019 and June 2022, 32 patients were enrolled, with 50.0% previously received systemic therapy. Among 28 patients with evaluable response, the confirmed ORR was 42.9%, the disease control rate was 82.1%, and the median progression-free survival (PFS) was 8.05 months. The confirmed ORR was 42.9% (6/14) in both treatment-naïve and previously treated patients. Notably, treatment-naïve patients had a median PFS of 11.89 months, and those with prior treatment had a median PFS of 6.47 months. Grade 3 treatment-related adverse events were transaminase elevation, rash, hyperbilirubinemia, proteinuria, hypertension, thrombocytopenia, hand-foot syndrome and diarrhea. No treatment-related deaths were observed. Higher tumor mutation burden (TMB), increased T-cell receptor (TCR) diversity, and altered receptor tyrosine kinase (RTK)/RAS pathway correlated with better tumor response. CONCLUSION: Camrelizumab plus apatinib provided promising antitumor activity with acceptable toxicity in patients with advanced MM. TMB, TCR diversity and RTK/RAS pathway genes were identified as potential predictive biomarkers and warrant further validation. TRIAL REGISTRATION NUMBER: Chinese Clinical Trial Registry, ChiCTR1900023277.

Making "cold" tumors "hot"- radiotherapy remodels the tumor immune microenvironment of pancreatic cancer to benefit from immunotherapy: a case report.

Immune checkpoint inhibitors have limited efficacy in metastatic pancreatic cancer due to the complex tumor immune microenvironment (TIME). Studies have shown that radiotherapy can cause cell lesions to release tumor antigens and then take part in the remodeling of the tumor environment and the induction of ectopic effects via regional and systemic immunoregulation. Here, we reported a case of advanced metastatic pancreatic cancer treated with immunotherapy combined with chemotherapy and radiotherapy and a sharp shift of the TIME from T3 to T2 was also observed. One hepatic metastasis within the planning target volume (PTV) was evaluated complete response (CR), the other one was evaluated partial response (PR) and 2 hepatic metastases outside the PTV were surprisingly considered PR. In the study, we found that immunotherapy combined with chemotherapy and radiotherapy achieved significant therapeutic benefits, which may provide a new strategy for the treatment of advanced pancreatic cancer.

Recent Progress on Therapeutic Vaccines for Breast Cancer.

Breast cancer remains the most frequently diagnosed malignancy worldwide. Advanced breast cancer is still an incurable disease mainly because of its heterogeneity and limited immunogenicity. The great success of cancer immunotherapy is paving the way for a new era in cancer treatment, and therapeutic cancer vaccination is an area of interest. Vaccine targets include tumor-associated antigens and tumor-specific antigens. Immune responses differ in different vaccine delivery platforms. Next-generation sequencing technologies and computational analysis have recently made personalized vaccination possible. However, only a few cases benefiting from neoantigen-based treatment have been reported in breast cancer, and more attention has been given to overexpressed antigen-based treatment, especially human epidermal growth factor 2-derived peptide vaccines. Here, we discuss recent advancements in therapeutic vaccines for breast cancer and highlight near-term opportunities for moving forward.

Case Report: Pathological Complete Response in a Lung Metastasis of Phyllodes Tumor Patient Following Treatment Containing Peptide Neoantigen Nano-Vaccine.

Some of the mutant peptides produced by gene mutation transcription and translation have the ability to induce specific T cells, which are called new antigens. Neoantigen-based peptide, DNA, RNA, and dendritic cell vaccines have been used in the clinic. In this paper, we describe a lung metastasis of a phyllodes tumor patient demonstrating pathological complete response following treatment containing personalized multi-epitope peptide neoantigen nano-vaccine. Based on whole-exome sequencing (WES), RNA sequencing, and new antigen prediction, several mutated peptide fragments were predicted to bind to the patient's human leukocyte antigen (HLA) allotypes, including ten peptides with high predicted binding affinity for six genes. The pulmonary metastases remained stable after the four cycles of anti-PD1 and anlotinib. After the addition of the multi-epitope peptide neoantigen nano-vaccine, the tumor began to collapse and contracture developed, accompanied by a decrease of tumor markers to normal, and complete pathological remission was achieved. With the use of the vaccination, recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) was used every time, and low-dose cyclophosphamide was injected every 3 weeks to improve efficacy. Peripheral blood immune monitoring demonstrated immune reactivity against a series of peptides, with the most robust post-vaccine T-cell response detected against the HLA-DRB1*0901-restricted SLC44A5 V54F peptide.

Therapeutic effect and safety of individualized chemotherapy combined with sequential immunotherapy based on BRCA1 mRNA expression level in unresectable pancreatic cancer.

Aim: We aimed to evaluate the efficacy and safety of individualized chemotherapy combined with sequential immunotherapy based on BRCA1 mRNA expression in unresectable pancreatic cancer. Methods: The expression of BRCA1 mRNA in tumor tissues of 25 patients with pancreatic cancer was detected in this retrospective study. Patients in the medium and high expression groups were treated with paclitaxel-based chemotherapy: albumin paclitaxel 125mg/m2, gemcitabine 1g/m2, day 1. Patients in the low expression group were treated with oxaliplatin-based chemotherapy: oxaliplatin 85mg/m2, gemcitabine 1g/m2, day 1. Sequential GM-CSF and IL-2 immunotherapy were applied. Patient condition, treatment efficacy and safety were assessed every 4 cycles. Results: A total of 25 patients were enrolled in the study. All of them were observed for toxic side effects and 24 of them were evaluated for efficacy. The median overall survival and median progression-free survival were 11.9 months and 6.3 months. The disease control rate was 91.7%, of which 37.5% (9/24) patients achieved partial remission (PR), 54.2% (13/24) patients achieved stable disease (SD) and 8.3% (2/24) patients were assessed as progressive disease(PD). Of the 15 patients with medium or high expression in BRCA1 mRNA, 7 achieved PR and 8 achieved SD. Of the 9 patients with low BRCA1 mRNA expression, 2 achieved PR, 5 achieved SD and 2 had PD. The proportion of eosinophils in the blood of some patients with good therapeutic effects was significantly higher than that before treatment. Hematological and non-hematological toxicity during the treatment were mostly grade 1~2. The two most common grade 3 to 4 adverse events were fever and thrombocytopenia. Conclusion: Our results suggest that individualized selection of chemotherapy combined with sequential immunotherapy according to BRCA1 mRNA expression level in unresectable pancreatic cancer could control the disease and have controllable adverse reactions.

Benefits of an Immunogenic Personalized Neoantigen Nanovaccine in Patients with High-Risk Gastric/Gastroesophageal Junction Cancer.

Personalized neoantigen vaccines have shown strong immunogenicity in clinical trial, but still face various challenges in facilitating an efficient antitumor immune response. Here, a personalized neoantigen nanovaccine (PNVAC) platform for adjuvant cancer immunotherapy is generated. PNVAC triggers superior protective efficacy against tumor recurrence and promotes longer survival than free neoantigens, especially when combined with anti-PD-1 treatment in a murine tumor model. A phase I clinical trial (ChiCTR1800017319) is initiated to evaluate the safety, immunogenicity, and prophylactic effect of PNVAC on preventing tumor recurrence in patients with high-risk gastric/gastroesophageal junction cancer after adjuvant chemotherapy of postsurgical resection. The one- and two-year disease-free survival rates are significantly higher than historical record. PNVAC induces both CD4+ and CD8+ T cell responses as well as antigen-experienced memory T cell phenotype. Furthermore, the immune response is persistent and remains evident one year after the vaccination. This work provides a safe and feasible strategy for developing neoantigen vaccines to delay gastric cancer recurrence after surgery.

AGIG Chemo-Immunotherapy in Patients With Advanced Pancreatic Cancer: A Single-Arm, Single-Center, Phase 2 Study.

BACKGROUND: To date, chemotherapy remains the only effective treatment of unresectable pancreatic adenocarcinoma. In the past few years, the interest in immunological anticancer therapy rises sharply. AGIG is a novel chemo-immunotherapy regimen that combines nab-paclitaxel + gemcitabine chemotherapy with sequential recombinant interleukin-2 (IL-2) and granulocyte-macrophage colony stimulating factor (GM-CSF) therapy. We conducted a single-arm prospective phase II study to determine the efficacy and safety of the first-line treatment of advanced pancreatic cancer with AGIG regimen. METHODS: Nab-paclitaxel (125 mg/m2) and gemcitabine (1000 mg/m2) were administered intravenously to all patients on days 1 and 8 triweekly, interleukin-2 (1000000U) and GM-CSF (100 µg) were administered subcutaneously on days 3-5 after chemotherapy. The primary end point was ORR by the Response Evaluation Criteria in Solid Tumors, version 1.1. Secondary end points included safety profile, progression-free survival (PFS), overall survival (OS). Patients' conditions along with the efficacy and safety were assessed every two cycles. RESULTS: Between 11/2018 and 01/2020, sixty-four patients were enrolled. In the sixty-four evaluable patients, the disease control rate (DCR) and overall response rate (ORR) were 76.6% and 43.75%, respectively. The median follow-up time was 12.1 (range 7.1-22.4) months. The median PFS was 5.7 (range 1.63-15.8) months. The median OS was 14.2 (range 2.9-22.0) months. The most common adverse event was fever (75%). The incidence of III/IV grade neutropenia was 4.69%. In subgroup analyses, we found that eosinophil count in the blood elevated three times higher than baseline level predicted a longer survival. CONCLUSIONS: The AGIG chemo-immunotherapy regimen has presented favorable ORR, OS, and manageable toxicities as first-line therapeutic strategy of advanced pancreatic cancer treatment. This regimen may be a novel reliable therapeutic option for patients with preserved performance status. The improvement of treatment efficiency may be related to the activation of non-specific immune response. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/. identifier NCT03768687.

Bifunctional iRGD-anti-CD3 enhances antitumor potency of T cells by facilitating tumor infiltration and T-cell activation.

BACKGROUND: Poor infiltration and limited activation of transferred T cells are fundamental factors impeding the development of adoptive cell immunotherapy in solid tumors. A tumor-penetrating peptide iRGD has been widely used to deliver drugs deep into tumor tissues. CD3-targeting bispecific antibodies represent a promising immunotherapy which recruits and activates T cells. METHODS: T-cell penetration was demonstrated in tumor spheroids using confocal microscope, and in xenografted tumors by histology and in vivo real-time fluorescence imaging. Activation and cytotoxicity of T cells were assessed by flow cytometry and confocal microscope. Bioluminescence imaging was used to evaluate in vivo antitumor effects, and transmission electron microscopy was used for mechanistic studies. RESULTS: We generated a novel bifunctional agent iRGD-anti-CD3 which could immobilize iRGD on the surface of T cells through CD3 engaging. We found that iRGD-anti-CD3 modification not only facilitated T-cell infiltration in 3D tumor spheroids and xenografted tumor nodules but also induced T-cell activation and cytotoxicity against target cancer cells. T cells modified with iRGD-anti-CD3 significantly inhibited tumor growth and prolonged survival in several xenograft mouse models, which was further enhanced by the combination of programmed cell death protein 1 (PD-1) blockade. Mechanistic studies revealed that iRGD-anti-CD3 initiated a transport pathway called vesiculovacuolar organelles in the endothelial cytoplasm to promote T-cell extravasation. CONCLUSION: Altogether, we show that iRGD-anti-CD3 modification is an innovative and bifunctional strategy to overcome major bottlenecks in adoptive cell therapy. Moreover, we demonstrate that combination with PD-1 blockade can further improve antitumor efficacy of iRGD-anti-CD3-modified T cells.

[Corrigendum] Tumor­penetrating peptide fused EGFR single­domain antibody enhances radiation responses following EGFR inhibition in gastric cancer.

Following the publication of the above article, the authors noticed that data shown in certain of the panels in Figs. 4 and 5 were selected incorrectly and presented wrongly in these figures. Essentially, in Fig. 4, the data shown for the Tunel, anti­EGFR­iRGD and Tunel, anti­EGFR­iGRD+IR data panels (i.e., the panels in the third row, columns 2 and 4), were chosen incorrectly, and in Fig. 5, the data panel for the Lung, IR experiment (fourth row, third column) was selected incorrectly. The revised versions of Figs. 4 and 5, featuring all the correct data panels, are shown on the next page. Furthermore, the results were re­analyzed based on the correct data. The errors made in the compilation of these Figures did not affect the overall conclusions reported in the paper. The authors are grateful to the Editor of Oncology Reports for allowing them the opportunity to publish this Corrigendum, and apologize to the readership for any inconvenience caused. [the original article was published in Oncology Reports 40: 1583-1591, 2018; DOI: 10.3892/or.2018.6532].

iRGD synergizes with PD-1 knockout immunotherapy by enhancing lymphocyte infiltration in gastric cancer.

Poor infiltration of activated lymphocytes into tumors represents a fundamental factor limiting the therapeutic effect of adoptive cell immunotherapy. A tumor-penetrating peptide, iRGD, has been widely used to deliver drugs into tumor tissues. In this study, we demonstrate for the first time that iRGD could also facilitate the infiltration of lymphocytes in both 3D tumor spheroids and several xenograft mouse models. In addition, combining iRGD modification with PD-1 knockout lymphocytes reveals a superior anti-tumor efficiency. Mechanistic studies demonstrate that the binding of iRGD to neuropilin-1 results in tyrosine phosphorylation of the endothelial barrier regulator VE-cadherin, which plays a role in the opening of endothelial cell contacts and the promotion of transendothelial lymphocyte migration. In summary, these results demonstrate that iRGD modification could promote tumor-specific lymphocyte infiltration, and thereby overcome the bottleneck associated with adoptive immune cell therapy in solid tumors.

Anti-EGFR-iRGD recombinant protein modified biomimetic nanoparticles loaded with gambogic acid to enhance targeting and antitumor ability in colorectal cancer treatment.

BACKGROUND: Red blood cell membrane-coated nanoparticle (RBCm-NP) platform, which consist of natural RBCm and synthetic polymeric core, can extend circulation time in vivo with an improved biocompatibility and stability of this biomimetic nanocarrier. To achieve better bioavailability of antitumor drugs that were loaded in RBCm-NPs, the functionalization of coated RBCm with specific targeting ability is essential. Bispecific recombinant protein anti-EGFR-iRGD, containing both tumor penetrating peptide (internalizing RGD peptide) and EGFR single-domain antibody (sdAb), seems to be an optimal targeting ligand for RBCm-NPs in the treatment of multiple tumors, especially colorectal cancer with high EGFR expression. MATERIALS AND METHODS: We modified the anti-EGFR-iRGD recombinant protein on the surface of RBCm-NPs by lipid insertion method to construct iE-RBCm-PLGA NPs and confirmed the presentation of active tumor-targeting ability in colorectal cancer models with high EGFR expression when compared with RBCm-PLGA NPs. In addition, potential anti-tumor drug gambogic acid (GA) was loaded into the NPs to endow the antitumor efficiency of iE-RBCm-GA/PLGA NPs. It was simultaneously evaluated whether GA can reach better biocompatibility benefiting from the improved antitumor efficiency of iE-RBCm-GA/PLGA NPs in colorectal cancer models. RESULTS: We successfully modified anti-EGFR-iRGD proteins on the surface of biomimetic NPs with integrated and stable "shell-core" structure. iE-RBCm-PLGA NPs showed its improved targeting ability in vitro (multicellular spheroids [MCS]) and in vivo (nude mice bearing tumors). Besides, no matter on short-term cell apoptosis at tumor site (terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling [TUNEL]) and long-term tumor inhibition, iE-RBCm-GA/PLGA NPs achieved better antitumor efficacy than free GA in spite of the similar effects of cytotoxicity and apoptosis to GA in vitro. CONCLUSION: We expect that the bispecific biomimetic nanocarrier can extend the clinical application of many other potential antitumor drugs similar to GA and become a novel drug carrier in the colorectal cancer treatment.

Enhancement of radiotherapeutic efficacy for esophageal cancer by paclitaxel-loaded red blood cell membrane nanoparticles modified by the recombinant protein anti-EGFR-iRGD.

Paclitaxel is widely used as a radiosensitizer for various tumors, including esophageal cancer, but its therapeutic effect remains to be improved. In this study, we constructed a novel nano-radiosensitizer, anti-EGFR-iRGD-conjugated (iE)-PRNPs, by conjugating the recombinant protein anti-epidermal growth factor receptor (EGFR)-internalizing arginine-glycine-aspartic (iRGD) to the surface of paclitaxel-loaded red blood cell membrane nanoparticles (PRNPs). The iE-PRNPs were confirmed to possess tumor-targeting, high penetrability, and sustained release properties that free paclitaxel does not possess. Compared with that of paclitaxel, the sensitizer enhancement ratio of iE-PRNPs was significantly increased (1.32-fold and 1.25-fold) in esophageal cancer cells with high and low expression levels of EGFR, respectively. Additionally, compared with that of unmodified PRNPs, the sensitizer enhancement ratio of iE-PRNPs in EGFR-overexpressing esophageal cancer cells was significantly increased (1.27-fold), while that of PRNPs in esophageal cancer cells with a low EGFR expression level increased slightly (1.06-fold). The improved radiosensitization effect was associated with enhanced G2/M arrest, increased reactive oxygen species, and more effective induction of DNA double-strand breaks. In summary, iE-PRNPs appear to be a novel type of radiosensitizer with the potential to overcome the bottleneck of esophageal cancer radiotherapeutic efficacy.

Bispecific tumor-penetrating protein anti-EGFR-iRGD efficiently enhances the infiltration of lymphocytes in gastric cancer.

Efficient trafficking of lymphocytes to the tumor microenvironment is crucial for the success of an effective antitumor immunotherapy. A major challenge to achieve effective adoptive immunotherapy is poor tumor penetration and inefficient migration of T cells to the tumor site. Several approaches to facilitate the trafficking of lymphocytes to the tumor microenvironment have been suggested to overcome these obstacles. Here, we address this issue with a focus on the tumor-penetrating peptide iRGD, which can specifically increase the permeability of the tumor vasculature and tumor tissue, enhancing drug penetration. We previously constructed a bispecific tumor-penetrating protein, anti-EGFR-iRGD, which consists of the variable region of the heavy chain of anti-EGFR antibody and a tumor-penetrating peptide iRGD, and verified its ability to improve the penetration of antitumor drugs. Herein, we introduce a novel method of co-administering T cells and anti-EGFR-iRGD to enhance the trafficking, penetration and antitumoral activity of T cells. Our results provide new insights for effectively enhancing T-cell infiltration in tumors and demonstrate a preclinical translational approach for the use of anti-EGFR-iRGD as a therapeutic modifier of cancer immunotherapy to improve clinical outcomes.

Tumor­penetrating peptide fused EGFR single­domain antibody enhances radiation responses following EGFR inhibition in gastric cancer.

Radiotherapy has been the primary method for the local control of several types of unresectable tumor, including gastric cancer. Patients with gastric cancer frequently express high levels of epidermal growth factor receptor (EGFR), which have been found to increase following radiotherapy treatment. This provides a basis for the combination of antibodies targeting EGFR and radiotherapy. In our previous study, a protein (anti­EGFR­iRGD) with bispecific targets and high permeability was constructed, and its effects on inhibiting the proliferation of gastric cancer cells was investigated. In the present study, the capacity of anti­EGFR­iRGD to modulate a radiation response was investigated and the specific mechanisms underlying these interactions were evaluated in gastric cancer cell lines and xenografts exhibiting high levels of EGFR. The radioenhancement of anti­EGFR­iRGD was associated with inhibited radiation­induced upregulation of EGFR, inhibited cell proliferation and promotion of cell apoptosis. In addition, anti­EGFR­iRGD appeared to permeate more into the tumor tissue following radiation. These findings indicated that the recombinant protein anti­EGFR­iRGD was a selective and effective radiosensitizer in EGFR­overexpressing gastric cancer cells and xenografts. These results further suggested that anti­EGFR­iRGD is a potential superior EGFR­targeted therapy combined with radiotherapy. Overall, the present study suggested that anti­EGFR­iRGD may be a promising candidate for preclinical and clinical use.

Lipid insertion enables targeted functionalization of paclitaxel-loaded erythrocyte membrane nanosystem by tumor-penetrating bispecific recombinant protein.

BACKGROUND: There is currently much interest in cancer cell targeting and tumor penetrating for research and therapeutic purposes. PURPOSE: To improve targeting delivery of antitumor drugs to gastric cancer, in this study, a tumor-targeting biocompatible drug delivery system derived from erythrocyte membrane for delivering paclitaxel (PTX) was constructed. METHODS: Erythrocyte membrane of human red blood cells (RBCs) were used for preparing of erythrocyte membrane-derived vesicles. 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-(maleimide[polyethylene glycol]-3400) (DSPE-PEG-MAL), a phospholipid derivative, was used to insert tumor-targeting molecular into erythrocyte membrane-derived vesicles. A lipid insertion method was used to functionalize these vesicles without the need for direct chemical conjugation. Furthermore, a tumor-penetrating bispecific recombinant protein named anti-EGFR-iRGD was used for the first time in this work to enable nanosystem to target and penetrate efficiently into the tumor site. RESULTS: Paclitaxel (PTX)-loaded anti-EGFR-iRGD-modified erythrocyte membrane nano-system (anti-EGFR-iRGD-RBCm-PTX, abbreviated to PRP) were manufactured. PRP was spheroid, uniformly size, about 171.7±4.7 nm in average, could be stable in vitro for 8 days, and released PTX in a biphasic pattern. PRP showed comparable cytotoxicity toward human gastric cancer cells in vitro. In vivo studies showed that, PRP accumulated in tumor site within 2 h of administration, lasted longer than 48 h, and the tumor volume was reduced 61% by PRP treatment in Balb/c nude mice, without causing severe side effects. CONCLUSION: PRP has potential applications in cancer treatment and as an adjunct for other anticancer strategies.