GPC3-targeted CAR-T cells expressing GLUT1 or AGK exhibit enhanced antitumor activity against hepatocellular carcinoma.

Chimeric antigen receptor-expressing T (CAR-T) cells induce robust antitumor responses in patients with hematologic malignancies. However, CAR-T cells exhibit only limited efficacy against solid tumors such as hepatocellular carcinoma (HCC), partially due to their limited expansion and persistence. CD8+ T cells, as key components of the adaptive immune response, play a central role in antitumor immunity. Aerobic glycolysis is the main metabolic feature of activated CD8+ T cells. In the tumor microenvironment, however, the uptake of large amounts of glucose by tumor cells and other immunosuppressive cells can impair the activation of T cells. Only when tumor-infiltrating lymphocytes (TILs) in the tumor microenvironment have a glycolytic advantage might the effector function of T cells be activated. Glucose transporter type 1 (GLUT1) and acylglycerol kinase (AGK) can boost glycolytic metabolism and activate the effector function of CD8+ T cells, respectively. In this study, we generated GPC3-targeted CAR-T cells overexpressing GLUT1 or AGK for the treatment of HCC. GPC3-targeted CAR-T cells overexpressing GLUT1 or AGK specifically and effectively lysed GPC3-positive tumor cells in vitro in an antigen-dependent manner. Furthermore, GLUT1 or AGK overexpression protected CAR-T cells from apoptosis during repeated exposures to tumor cells. Compared with second-generation CAR-T cells, GPC3-targeted CAR-T cells overexpressing GLUT1 or AGK exhibited greater CD8+ T-cell persistence in vivo and better antitumor effects in HCC allograft mouse models. Finally, we revealed that GLUT1 or AGK maintained anti-apoptosis ability in CD8+ T cells via activation of the PI3K/Akt pathway. This finding might identify a therapeutic strategy for advanced HCC.

Clinicopathological significance and immunotherapeutic outcome of claudin 18.2 expression in advanced gastric cancer: A retrospective study.

Objective: Immunotherapeutic outcomes and clinical characteristics of claudin 18 isoform 2 positive (CLDN18.2-positive) gastric cancer (GC) vary in different clinical studies, making it difficult to optimize anti-CLDN18.2 therapy. We conducted a retrospective analysis to explore the association of CLDN18.2 expression with clinicopathological characteristics and immunotherapeutic outcomes in GC. Methods: A total of 536 advanced GC patients from 2019 to 2021 in the CT041-CG4006 and CT041-ST-01 clinical trials were included in the analysis. CLDN18.2 expression on ≥40% of tumor cells (2+, 40%) and CLDN18.2 expression on ≥70% of tumor cells (2+, 70%) were considered the two levels of positively expressed GC. The clinicopathological characteristics and immunotherapy outcomes of GC patients were analyzed according to CLDN18.2 expression status. Results: CLDN18.2 was expressed in 57.6% (cut-off: 2+, 40%) and 48.9% (cut-off: 2+, 70%) of patients. Programmed death-ligand 1 (PD-L1) and CLDN18.2 were co-expressed in 19.8% [combined positive score (CPS)≥1, CLDN18.2 (cut-off: 2+, 40%)] and 17.2% [CPS≥5, CLDN18.2 (cut-off: 2+, 70%)] of patients. CLDN18.2 expression positively correlated with younger age, female sex, non-gastroesophageal junction (non-GEJ), and diffuse phenotype (P<0.001). HER2 and PD-L1 expression were significantly lower in CLDN18.2-positive GC (both P<0.05). Uterine adnexa metastasis (P<0.001) was more frequent and liver metastasis (P<0.001) was less common in CLDN18.2-positive GC. Overall survival and immunotherapy-related progression-free survival (irPFS) were inferior in the CLDN18.2-positive group. Conclusions: CLDN18.2-positive GC is associated with poor prognosis and worse immunotherapeutic outcomes. The combination of anti-CLDN18.2 therapy, anti-PD-L1/PD-1 therapy, and chemotherapy for GC requires further investigation.

Metastatic gastric cancer target lesion complete response with Claudin18.2-CAR T cells.

Treatment of hematologic malignancies with patient-derived anti-CD19 chimeric antigen receptor (CAR) T-cells has demonstrated long-term remissions for patients with otherwise treatment-refractory advanced leukemia and lymphoma. Conversely, CAR T-cell treatment of solid tumors, including advanced gastric cancer (GC), has proven more challenging due to on-target off-tumor toxicities, poor tumor T-cell infiltration, inefficient CAR T-cell expansion, immunosuppressive tumor microenvironments, and demanding preconditioning regimens. We report the exceptional results of autologous Claudin18.2-targeted CAR T cells (CT041) in a patient with metastatic GC, who had progressed on four lines of combined systemic chemotherapy and immunotherapy. After two CT041 infusions, the patient had target lesion complete response and sustained an 8-month overall partial response with only minimal ascites. Moreover, tumor-informed circulating tumor DNA (ctDNA) reductions coincided with rapid CAR T-cell expansion and radiologic response. No severe toxicities occurred, and the patient's quality of life significantly improved. This experience supports targeting Claudin18.2-positive GC with CAR T-cell therapy and helps to validate ctDNA as a biomarker in CAR T-cell therapy. Clinical Insight: Claudin18.2-targeted CAR T cells can safely provide complete objective and ctDNA response in salvage metastatic GC.

CXCR4-modified CAR-T cells suppresses MDSCs recruitment via STAT3/NF-κB/SDF-1α axis to enhance efficacy against pancreatic cancer.

Claudin18.2 (CLDN18.2)-specific chimeric antigen receptor (CAR-T) cells displayed limited efficacy in CLDN18.2-positive pancreatic ductal adenocarcinoma (PDAC). Strategies are needed to improve the trafficking capacity of CLDN18.2-specific CAR-T cells. PDAC has a unique microenvironment that consists of abundant cancer-associated fibroblasts (CAFs), which could secrete stromal cell-derived factor 1α (SDF-1α), the ligand of CXCR4. Then, we constructed and explored CLDN18.2-targeted CAR-T cells with CXCR4 co-expression in treating immunocompetent mouse models of PDAC. The results indicated that CXCR4 could promote the infiltration of CAR-T cells and enhance their efficacy in vivo. Mechanistically, the activation of signal transducer and activator of transcription 3 (STAT3) signaling was impaired in CXCR4 CAR-T cells, which reduced the release of inflammatory factors, such as tumor necrosis factor-α, IL-6, and IL-17A. Then, the lower release of inflammatory factors suppressed SDF-1α secretion in CAFs via the nuclear factor κB (NF-κB) pathway. Therefore, the decreased secretion of SDF-1α in feedback decreased the migration of myeloid-derived suppressor cells (MDSCs) in tumor sites. Overall, our study demonstrated that CXCR4 CAR-T cells could traffic more into tumor sites and also suppress MDSC migration via the STAT3/NF-κB/SDF-1α axis to obtain better efficacy in treating CLDN18.2-positive pancreatic cancer. Our findings provide a theoretical rationale for CXCR4 CAR-T cell therapy in PDAC.

RUNX-3-expressing CAR T cells targeting glypican-3 in patients with heavily pretreated advanced hepatocellular carcinoma: a phase I trial.

Background: Glypican-3 (GPC3) is a well-characterized hepatocellular carcinoma (HCC)-associated antigen and a promising target for HCC treatment. CT017 CAR T cells were engineered to co-express CAR-GPC3 and runt-related transcription factor 3 (RUNX3), which triggers CD8+ T-cell infiltration into the cancer microenvironment. Methods: This single-center, single-arm, open-label, phase I clinical study enrolled heavily pretreated patients with GPC3-positive HCC between August 2019 and December 2020 (NCT03980288). Patients were treated with CT017 CAR T cells at a dose of 250 × 106 cells. The primary objective was to assess the safety and tolerability of this first-in-human product. Findings: Six patients received 7 infusions (one patient received 2 infusions) at the 250 × 106 cells dose. Three patients received CT017 monotherapy, and three patients received CT017-tyrosine kinase inhibitor (TKI) combination therapy at the first infusion. One patient received CT017-TKI combination therapy at the second infusion after CT017 monotherapy. All patients experienced cytokine release syndrome (CRS), with 50% (3/6) at Grade 2, 50% (3/6) at Grade 3, and all events resolved after treatment. No immune effector cell-associated neurotoxicity syndrome was observed. Dose escalation was not performed due to the investigator's decision regarding safety. Of six evaluable patients, one achieved partial response and two had stable disease for a 16.7% objective response rate, 50% disease control rate, 3.5-month median progression-free survival, 3.2-month median duration of disease control, and 7.9-month median overall survival (OS) with 7.87-month median follow-up. The longest OS was 18.2 months after CT017 infusion. Interpretation: Current preliminary phase I data showed a manageable safety profile and promising antitumor activities of CT017 for patients with advanced HCC. These results need to be confirmed in a robust clinical trial. Funding: This study was funded by CARsgen Therapeutics Co., Ltd.

FAP-targeted CAR-T suppresses MDSCs recruitment to improve the antitumor efficacy of claudin18.2-targeted CAR-T against pancreatic cancer.

PURPOSE: The claudin 18.2 (CLDN18.2) antigen is frequently expressed in malignant tumors, including pancreatic ductal adenocarcinoma (PDAC). Although CLDN18.2-targeted CAR-T cells demonstrated some therapeutic efficacy in PDAC patients, further improvement is needed. One of the major obstacles might be the abundant cancer-associated fibroblasts (CAFs) in the PDAC tumor microenvironment (TME). Targeting fibroblast activation protein (FAP), a vital characteristic of CAFs provides a potential way to overcome this obstacle. In this study, we explored the combined antitumor activity of FAP-targeted and CLDN18.2-targeted CAR-T cells against PDAC. METHODS: Novel FAP-targeted CAR-T cells were developed. Sequential treatment of FAP-targeted and CLDN18.2-targeted CAR-T cells as well as the corresponding mechanism were explored in immunocompetent mouse models of PDAC. RESULTS: The results indicated that the priorly FAP-targeted CAR-T cells infusion could significantly eliminate CAFs and enhance the anti-PDAC efficacy of subsequently CLDN18.2-targeted CAR-T cells in vivo. Interestingly, we observed that FAP-targeted CAR-T cells could suppress the recruitment of myeloid-derived suppressor cells (MDSCs) and promote the survival of CD8+ T cells and CAR-T cells in tumor tissue. CONCLUSION: In summary, our finding demonstrated that FAP-targeted CAR-T cells could increase the antitumor activities of sequential CAR-T therapy via remodeling TME, at least partially through inhibiting MDSCs recruitment. Sequential infusion of FAP-targeted and CLDN18.2-targeted CAR-T cells might be a feasible approach to enhance the clinical outcome of PDAC.

Enforced expression of Runx3 improved CAR-T cell potency in solid tumor via enhancing resistance to activation-induced cell death.

Limited T cell persistence restrains chimeric antigen receptor (CAR)-T cell therapy in solid tumors. To improve persistence, T cells have been engineered to secrete proinflammatory cytokines, but other possible methods have been understudied. Runx3 has been considered a master regulator of T cell development, cytotoxic T lymphocyte differentiation, and tissue-resident memory T (Trm)-cell formation. A study using a transgenic mouse model revealed that overexpression of Runx3 promoted T cell persistence in solid tumors. Here, we generated CAR-T cells overexpressing Runx3 (Run-CAR-T cells) and found that Run-CAR-T cells had long-lasting antitumor activities and achieved better tumor control than conventional CAR-T cells. We observed that more Run-CAR-T cells circulated in the peripheral blood and accumulated in tumor tissue, indicating that Runx3 coexpression improved CAR-T cell persistence in vivo. Tumor-infiltrating Run-CAR-T cells showed less cell death with enhanced proliferative and effector activities. Consistently, in vitro studies indicated that AICD was also decreased in Run-CAR-T cells via downregulation of tumor necrosis factor (TNF) secretion. Further studies revealed that Runx3 could bind to the TNF promoter and suppress its gene transcription after T cell activation. In conclusion, Runx3-armored CAR-T cells showed increased antitumor activities and could be a new modality for the treatment of solid tumors.

Long term complete response of advanced hepatocellular carcinoma to glypican-3 specific chimeric antigen receptor T-Cells plus sorafenib, a case report.

The clinical efficacy of current therapies for Hepatocellular carcinoma (HCC) are unsatisfactory. In recent years, chimeric antigen receptor (CAR) T-cell therapies have been developed for solid tumors including advanced HCC (aHCC), but limited progress has been made. Glypican-3 is a promising immunotherapeutic target for HCC since it is specifically highly expressed in HCC. A previous study indicated that GPC3-targeted CAR T-(CAR-GPC3) cells were well-tolerated and had prolonged survival for HCC patients and that Sorafenib could increase the antitumor activities of CAR-GPC3 T-cells against HCC in mouse models. Here, we report a patient with aHCC who achieved a complete response (CR) and a long survival period after the combination therapy of CAR-GPC3 T-cell plus sorafenib. A 60-year-old Asian male diagnosed with hepatitis B virus (HBV) related HCC developed liver recurrence and lung metastasis after liver tumor resection and trans-arterial chemoembolization therapy. The patient also previously received microwave ablation therapy for lung metastasis. After the enrollment, the patient underwent leukapheresis for CAR-GPC3 T-cells manufacturing. Seven days after leukapheresis, the patient started to receive 400 mg of Sorafenib twice daily. The patient received 4 cycles of CAR-GPC3 T cells (CT011) treatment and each cycle was divided into two infusions. Prior to each cycle of CT011 treatment, lymphodepletion was performed. The lymphodepletion regimen was cyclophosphamide 500 mg/m2/day for 2 to 3 days, and fludarabine 20-25 mg/m2/day for 3 to 4 days. A total of 4×109 CAR-GPC3 T cells were infused. The CT011 plus Sorafenib combination therapy was well tolerated. All the ≥ grade 3 AEs were hematological toxicities which were deemed an expected event caused by the preconditioning regimen. This patient obtained partial responses from the 3rd month and achieved CR in the 12th month after the first cycle of CT011 infusion according to the RECIST1.1 assessment. The tumor had no progression for more than 36 months and maintained the CR status for more than 24 months after the first infusion.

Radiation enhances the efficacy of EGFR-targeted CAR-T cells against triple-negative breast cancer by activating NF-κB/Icam1 signaling.

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype, with limited treatment options. Epidermal growth factor receptor (EGFR) is reported to be expressed in 50%-75% of TNBC patients, making it a promising target for cancer treatment. Here we show that EGFR-targeted chimeric antigen receptor (CAR) T cell therapy combined with radiotherapy provides enhanced antitumor efficacy in immunocompetent and immunodeficient orthotopic TNBC mice. Intriguingly, this combination therapy resulted in a substantial increase in the number of tumor-infiltrating CAR-T cells. The efficacy of this combination was independent of tumor radiosensitivity and lymphodepleting preconditioning. Cytokine profiling showed that this combination did not increase the risk of cytokine release syndrome (CRS). RNA sequencing (RNA-seq) analysis revealed that EGFR-targeting CAR-T therapy combined with radiotherapy increased the infiltration of CD8+ T and natural killer (NK) cells into tumors. Mechanistically, radiation significantly increased Icam1 expression on TNBC cells via activating nuclear factor κB (NF-κB) signaling, thereby promoting CAR-T cell infiltration and killing. These results suggest that CAR-T therapy combined with radiotherapy may be a promising strategy for TNBC treatment.

Chimeric anti-GPC3 sFv-CD3ε receptor-modified T cells with IL7 co-expression for the treatment of solid tumors.

Chimeric antigen receptor (CAR) T cells targeting glypican-3 (GPC3) demonstrated early signs of therapeutic efficacy to hepatocellular carcinoma patients with a risk of cytokine release syndrome (CRS). Several adoptive cell therapies (ACTs) with T cells using the natural T cell receptor (TCR) signaling induced more efficient antitumor function and reduced cytokine production relative to CARs in solid tumors. To improve the efficacy and safety of GPC3-targeted ACTs, T cells were modified with anti-GPC3 single-chain fragment variable(sFv) linked to CD3ε, which could be incorporated into the entire TCR/CD3 complex to form chimeric sFv-CD3ε receptor (sFv-ε). sFv-ε T cells showed competitive antitumor activity and lower cytokine release compared to 28ζ or BBζ CAR T cells, which may be ascribed to moderately less activated Ca2+-calcineurin-NFAT signaling pathway. We further generated murine sFv-ε T cells with interleukin-7 co-expression (7sFv-ε) to promote T cell survival and to mobilize the endogenous immune system. In immunocompetent mouse models, 7sFv-ε T cells showed superior persistence, antitumor efficacy, and immunological memory while preserving the low production of cytokines associated with CRS compared to conventional sFv-ε T cells. These results indicate that GPC3-specific 7sFv-ε T cells could serve as a promising therapeutic strategy for solid tumors.

Claudin18.2-specific CAR T cells in gastrointestinal cancers: phase 1 trial interim results.

Despite success in hematologic malignancies, the treatment landscape of chimeric antigen receptor (CAR) T cell therapy for solid tumors remains limited. Claudin18.2 (CLDN18.2)-redirected CAR T cells showed promising efficacy against gastric cancer (GC) in a preclinical study. Here we report the interim analysis results of an ongoing, open-label, single-arm, phase 1 clinical trial of CLDN18.2-targeted CAR T cells (CT041) in patients with previously treated, CLDN18.2-positive digestive system cancers ( NCT03874897 ). The primary objective was safety after CT041 infusion; secondary objectives included CT041 efficacy, pharmacokinetics and immunogenicity. We treated 37 patients with one of three CT041 doses: 2.5 × 108, 3.75 × 108 or 5.0 × 108 cells. All patients experienced a grade 3 or higher hematologic toxicity. Grade 1 or 2 cytokine release syndrome (CRS) occurred in 94.6% of patients. No grade 3 or higher CRS or neurotoxicities, treatment-related deaths or dose-limiting toxicities were reported. The overall response rate (ORR) and disease control rate (DCR) reached 48.6% and 73.0%, respectively. The 6-month duration of response rate was 44.8%. In patients with GC, the ORR and DCR reached 57.1% and 75.0%, respectively, and the 6-month overall survival rate was 81.2%. These initial results suggest that CT041 has promising efficacy with an acceptable safety profile in patients with heavily pretreated, CLDN18.2-positive digestive system cancers, particularly in those with GC.

Olaparib Suppresses MDSC Recruitment via SDF1α/CXCR4 Axis to Improve the Anti-tumor Efficacy of CAR-T Cells on Breast Cancer in Mice.

A hostile tumor microenvironment is one of the major obstacles for the efficacy of chimeric antigen receptor modified T (CAR-T) cells, and combination treatment might be a potential way to overcome this obstacle. Poly(ADP-ribose) polymerase inhibitor (PARPi) has demonstrated tremendous potential in breast cancer. In this study, we explored the possible combination of the PAPRi olaparib with EGFRvIII-targeted CAR (806-28Z CAR) T cells in immunocompetent mouse models of breast cancer. The results indicated that the administration of olaparib could significantly enhance the efficacy of 806-28Z CAR-T cells in vivo. Interestingly, we observed that olaparib could suppress myeloid-derived suppressor cell (MDSC) migration and promote the survival of CD8+ T cells in tumor tissue. Mechanistically, olaparib was shown to reduce the expression of SDF1α released from cancer-associated fibroblasts (CAFs) and thereby decreased MDSC migration through CXCR4. Taken together, this study demonstrated that olaparib could increase the antitumor activities of CAR-T cell therapy at least partially through inhibiting MDSC migration via the SDF1α/CXCR4 axis. These findings uncover a novel mechanism of PARPi function and provide additional mechanistic rationale for combining PARPi with CAR-T cells for the treatment of breast cancer.

Coexpression of IL7 and CCL21 Increases Efficacy of CAR-T Cells in Solid Tumors without Requiring Preconditioned Lymphodepletion.

PURPOSE: T-cell recruitment, survival, and proliferation are the important limitations to chimeric antigen receptor (CAR) T cells therapy in the treatment of solid tumors. In this study, we engineered CAR-T cells to coexpress cytokines IL7 and CCL21 (7 × 21 CAR-T), a cytokine combination in order to improve proliferation and chemotaxis of CAR-T cells. EXPERIMENTAL DESIGN: CLDN18.2-specific second-generation CAR-T cells coexpressing cytokines were prepared using retroviral vector transduction. The proliferation and migration of genetically engineered CAR-T cells were evaluated in vitro. The antitumor activities of genetically engineered CAR-T cells were evaluated against multiple solid tumors in C57BL/6 mice in vivo. RESULTS: In vitro, the proliferation and chemotaxis of 7 × 21 CAR-T cells are significantly improved when compared with those of the conventional CAR-T cells. In vivo, 7 × 21 CAR-T cells revealed superior therapeutic effects to either conventional CAR-T cells or 7 × 19 CAR-T cells which coexpress IL7 and CCL19 as previously reported in three different solid tumors without cyclophosphamide precondition. Interestingly, 7 × 21 CAR-T cells could also suppress the tumor growth with heterogeneous antigen expression and even induce tumor complete remission. Mechanistically, IL7 and CCL21 significantly improved survival and infiltration of CAR-T cells and dendritic cells in tumor. In addition, CCL21 also inhibited the tumor angiogenesis as proved by IHC. CONCLUSIONS: Coexpression of IL7 and CCL21 could boost CAR-T cells' antitumor activity, and 7 × 21 CAR-T cells may be served as a promising therapy strategy for solid tumors.

LRCH1 deficiency enhances LAT signalosome formation and CD8+ T cell responses against tumors and pathogens.

CD8+ T cells play pivotal roles in eradicating pathogens and tumor cells. T cell receptor (TCR) signaling is vital for the optimal activation of CD8+ T cells. Upon TCR engagement, the transmembrane adapter protein LAT (linker for activation of T cells) recruits other key signaling molecules and forms the "LAT signalosome" for downstream signal transduction. However, little is known about which functional partners could restrain the formation of the LAT signalosome and inhibit CD8+ cytotoxic T lymphocyte (CTL)-mediated cytotoxicity. Here we have demonstrated that LRCH1 (leucine-rich repeats and calponin homology domain containing 1) directly binds LAT, reduces LAT phosphorylation and interaction with GRB2, and also promotes the endocytosis of LAT. Lrch1-/- mice display better protection against influenza virus and Listeria infection, with enhanced CD8+ T cell proliferation and cytotoxicity. Adoptive transfer of Lrch1-/- CD8+ CTLs leads to increased B16-MO5 tumor clearance in vivo. Furthermore, knockout of LRCH1 in human chimeric antigen receptor (CAR) T cells that recognize the liver tumor-associated antigen glypican-3 could improve CAR T cell migration and proliferation in vitro. These findings suggest LRCH1 as a potential translational target to improve T cell immunotherapy against infection and tumors.

Chimeric Antigen Receptor-Glypican-3 T-Cell Therapy for Advanced Hepatocellular Carcinoma: Results of Phase I Trials.

PURPOSE: Our preclinical studies demonstrated the potential of chimeric antigen receptor (CAR)-glypican-3 (GPC3) T-cell therapy for hepatocellular carcinoma (HCC). We report herein the first published results of CAR-GPC3 T-cell therapy for HCC. PATIENTS AND METHODS: In two prospective phase I studies, adult patients with advanced GPC3+ HCC (Child-Pugh A) received autologous CAR-GPC3 T-cell therapy following cyclophosphamide- and fludarabine-induced lymphodepletion. The primary objective was to assess the treatment's safety. Adverse events were graded using the Common Terminology Criteria for Adverse Events (version 4.03). Tumor responses were evaluated using the RECIST (version 1.1). RESULTS: A total of 13 patients received a median of 19.9 × 108 CAR-GPC3 T cells by a data cutoff date of July 24, 2019. We observed pyrexia, decreased lymphocyte count, and cytokine release syndrome (CRS) in 13, 12, and nine patients, respectively. CRS (grade 1/2) was reversible in eight patients. One patient experienced grade 5 CRS. No patients had grade 3/4 neurotoxicity. The overall survival rates at 3 years, 1 year, and 6 months were 10.5%, 42.0%, and 50.3%, respectively, according to the Kaplan-Meier method. We confirmed two partial responses. One patient with sustained stable disease was alive after 44.2 months. CAR T-cell expansion tended to be positively associated with tumor response. CONCLUSIONS: This report demonstrated the initial safety profile of CAR-GPC3 T-cell therapy. We observed early signs of antitumor activity of CAR-GPC3 T cells in patients with advanced HCC.

Cryopreserved biopsy tissues of rectal cancer liver metastasis for assessment of anticancer drug response in vitro and in vivo.

Living tumors are of great scientific value for clinical medicine and basic research, especially for drug testing. An increasing number of drug tests fail due to the use of imperfect models. The aim of the present study was to develop a novel method combining vitrification­based cryopreservation of tumor biopsies and precision­cut slice cultivation for the assessment of anticancer drug responses. Biological characteristics of rectal cancer liver metastasis biopsies could be retained by vitrification­based cryopreservation. The patient­derived xenograft models were successfully established using both fresh and warmed biopsy tissues. Precision­cut slicing provided a similar three­dimensional architecture and heterogeneity to the original tumor. The positive drug responses in the xenograft model were consistent with those in precision­cut slice cultures in vitro. The present study demonstrated that live tumor biopsies could be preserved using vitrification­based cryopreservation. The warmed tissues developed xenograft tumors, which were also useful for either in vivo or in vitro anticancer drug testing. Precision­cut slices derived from the warmed tissues provided an efficient tool to assess anticancer drug response in vitro.

Genetically engineered T cells for cancer immunotherapy.

T cells in the immune system protect the human body from infection by pathogens and clear mutant cells through specific recognition by T cell receptors (TCRs). Cancer immunotherapy, by relying on this basic recognition method, boosts the antitumor efficacy of T cells by unleashing the inhibition of immune checkpoints and expands adaptive immunity by facilitating the adoptive transfer of genetically engineered T cells. T cells genetically equipped with chimeric antigen receptors (CARs) or TCRs have shown remarkable effectiveness in treating some hematological malignancies, although the efficacy of engineered T cells in treating solid tumors is far from satisfactory. In this review, we summarize the development of genetically engineered T cells, outline the most recent studies investigating genetically engineered T cells for cancer immunotherapy, and discuss strategies for improving the performance of these T cells in fighting cancers.

An IL-4/21 Inverted Cytokine Receptor Improving CAR-T Cell Potency in Immunosuppressive Solid-Tumor Microenvironment.

Incorporation of inverted cytokine receptor (ICR) such as interleukin (IL)-4 vs. IL-7 (4/7) ICR is one strategy to improve the antitumor activities of chimeric antigen receptor (CAR) modified T (CAR-T) cells facing immunosuppressive cytokines. Here we report a novel interleukin (IL)-4 vs. IL-21 ICR (4/21 ICR) that enhanced CAR-T cell potency in IL-4+ tumor milieu via a different working-mechanism from 4/7 ICR. Upon IL-4 stimulation, 4/21 ICR activated the STAT3 pathway and promoted Th17-like polarization and tumor-targeted cytotoxicity in CAR-T cells in vitro. Furthermore, 4/21 ICR-CAR T cells persisted and eradicated established IL-4+ tumors in vivo. Thus, 4/21 ICR is a promising clinical CAR-T cell therapeutics for solid tumors rich in IL-4.