Targeted therapeutics have transformed cancer treatment by selectively eliminating malignant cells while limiting systemic toxicity. L-asparaginase (L-ASNase), which induces metabolic stress by depleting asparagine (Asn), is clinically used for hematological malignancies but shows limited activity against solid tumors due to poor delivery and an immunosuppressive microenvironment. We previously developed CRT3LP, a calreticulin (CRT)-targeting monobody-L-ASNase fusion protein, designed to exploit immunogenic cell death (ICD); however, its therapeutic potential is constrained by insufficient immune activation. Here, we show that CRT3LFP, a multifunctional fusion protein incorporating the flagellin B subunit (FlaB) into the CRT3LP scaffold, effectively promotes M2-to-M1 macrophage polarization while maintaining tumor-selective metabolic disruption. In combination with the tumor-colonizing bacterial strain CNC018, which induces surface-exposed CRT, CRT3LFP achieves precise tumor localization. This synergistic approach significantly inhibits tumor growth and reshapes the tumor microenvironment, characterized by enhanced macrophage polarization, dendritic cell maturation, and CD8+ T-cell expansion. Additionally, CD47 blockade further potentiates this effect, fostering the formation of durable immune memory. Together, our findings establish CRT3LFP as a tumor-targeted immunometabolic platform that integrates metabolic deprivation with coordinated innate and adaptive immune activation to overcome resistance in solid tumors.

Radiopharmaceutical therapy (RPT) represents a critical approach in oncology, nevertheless its efficacy may be limited by tumor resistance mechanisms associated with metabolic reprogramming. Enhancing tumor radiosensitivity remains a major challenge. Engineered bi-functional starvation probes (CRT3LP and CRT4LP) that simultaneously target ecto-CRT and exert L-ASNase activity are explored for disrupting tumor amino acid metabolism. Herein, we systematically evaluate the ability of targeted starvation probes to enhance antitumor efficacy in radioactive iodine (RAI) therapy. In vitro, the probes upregulated p53 expression while downregulating Rev1 and SOD2, thereby impairing ROS scavenging and sensitizing tumor cells to RAI-induced oxidative stress. In vivo, the combination treatment elevated intratumoral ROS levels, increased CD4⁺ and CD8⁺ T cell infiltration, upregulated pro-inflammatory cytokines (IFN-γ and TNF-α), and reduced regulatory T cell populations. Additionally, markers of tumor proliferation (Ki67 and CD31) were suppressed, while apoptotic markers (TUNEL and p21) were increased. Co-administration of the immune checkpoint inhibitor αPD-L1 further improved therapeutic efficacy. These findings suggest that targeted tumor starvation probes boost radiosensitivity and anti-tumor immunity, and this strategy shows improved efficacy in combination with αPD-L1 therapy.

Estrogen-related receptor-α (ERRα; NR3B1) is an orphan nuclear receptor that drives the progression of several cancers. To develop novel ERRα-targeting therapeutics, we designed and evaluated the function of a new compound, PAMT-001, which interacts with ERRα and effectively suppresses tumorigenesis. We demonstrated a significant interaction between ERRα and PAMT-001 using protein-small molecule binding assays and luciferase assays. Although PAMT-001 exhibited lower activity compared to the established ERRα inverse agonist XCT-790, it showed stronger anticancer effects against both hematological and solid tumors. Mechanistically, PAMT-001 promoted combined cell death mechanisms in tumors. It disrupted mitochondrial respiratory function and structure, leading to excessive production of reactive oxygen species and endoplasmic reticulum stress, ultimately resulting in apoptotic cell death. Additionally, PAMT-001 induced excessive autophagy, contributing to cancer cell death, as well as gasdermin E-mediated pyroptosis in acute myeloid leukemia and colon cancer cells. Furthermore, PAMT-001 demonstrated potential for use in precision medicine, particularly for patients with chemotherapy-resistant and NPM1-mutated acute myeloid leukemia. PAMT-001 is a potent ERRα-targeting anticancer agent capable of inducing anticancer effects through pyroptosis, autophagic cell death, and apoptosis-a newly termed mechanism referred to as "PAAoptosis." It holds significant potential for the treatment of both hematological and solid cancers.

Rationale:The immunosuppressive tumor microenvironment (TME) remains a major barrier to the efficacy of immune checkpoint blockade (ICB) therapy, underscoring the need for strategies that can safely reprogram the TME to enhance cancer immunity. Methods:Here, we developed CNC018, a clinically translatable Salmonella typhimurium (SL) strain designed to reprogram the TME and potentiate responses to ICB. CNC018 was constructed using the ppGpp-defective Salmonella strain (SL∆ppGpp, ΔrelA/ΔspoT deletion) as a genetic backbone, with the additional deletion of Salmonella pathogenicity island 1 and 2 (SPI-1 and SPI-2), which are essential for host cell invasion and intracellular survival. These modifications effectively eliminated the risk of virulence restoration. Results:CNC018 exhibited markedly reduced intracellular invasiveness, was rapidly cleared from non-tumor tissues, and displayed a 2.2-fold higher median lethal dose compared with SL∆ppGpp. Preferentially accumulating within tumors, CNC018 inhibited both primary and metastatic tumor growth in murine, human, and patient-derived xenograft models. CNC018 also induced tumor-derived damage-associated molecular patterns, which activated DCs and tumor-specific CD8⁺ T cells through the TLR4-NF-κB, JAK-STAT-IRF1, and NLRP3 inflammasome signaling pathways. Flow cytometry and single-cell RNA-sequencing revealed that CNC018 dramatically modulated immune checkpoint expression in the TME and tumor-draining lymph nodes, upregulating PD-L1 on tumor cells and dendritic cells and CTLA-4 on regulatory T cells, while downregulating PD-1 on effector T cells. This checkpoint modulation sensitized tumors to anti-PD-L1 and anti-CTLA-4 therapy, achieving synergistic tumor eradication and inducing durable, tumor-specific T-cell memory against tumor rechallenge. Conclusions:CNC018 represents a promising next-generation bacterial adjuvant with strong translational potential to safely enhance ICB efficacy in clinical cancer therapy.

Purpose of the Report The usefulness of brain 18 F-FDG PET/CT in primary central nervous system lymphoma (PCNSL) remains underexplored. This study investigated whether early metabolic responses in interim brain FDG PET/CT serve as a prognostic indicator of PCNSL treatment outcomes. Patients and Methods This prospective study included 53 patients with PCNSL who underwent a high-dose methotrexate–based treatment. Brain FDG PET was performed at diagnosis (baseline PET) and after induction chemotherapy (interim PET), assessing interim PET parameters such as the highest maximum standardized uptake value (hSUV max ), sum of SUV max (sumSUV max ), highest tumor-to-normal ratio (hTNR max ), sum of TNR max (sumTNR max ), highest metabolic tumor volume (MTV) (hMTV), and sum of MTV (sumMTV) across all PET-positive lesions. Results High interim hTNR max (hazards ratio: 9.76, 95% confidence interval: 1.90–50.11, P = 0.01) was an independently significant predictor of poor progression-free survival in multivariate analysis. Patients with low interim hTNR max (≤1.0) had a significantly longer median progression-free survival than those with high interim hTNR max (>1.0) (25.0 vs 3.6 months, P < 0.001). Incorporating interim MRI-based clinical response assessments and hTNR max allowed the classification of partial response subgroups with markedly different prognoses ( P < 0.001). High interim hTNR max (hazards ratio: 2.76, 95% confidence interval: 1.39–5.48, P = 0.004) was an independently significant predictor of poor overall survival in multivariate analysis. Conclusions The hTNR max measurement from interim brain FDG PET scans emerges as an important prognostic marker in PCNSL. These findings underscore the potential of interim FDG PET evaluations to refine response assessments and inform tailored therapeutic strategies.

Infections caused by nontuberculous mycobacteria, such as Mycobacterium avium and Mycobacteroides abscessus, are becoming increasingly prevalent, and rising antibiotic resistance poses a significant clinical challenge. However, the mechanisms by which the host defense system controls these infections remain poorly understood. Here we show that the autophagy-related protein ATG7 in innate immune cells plays an essential role in controlling nontuberculous mycobacterial infection and protecting lung tissue from pathological inflammation. Patients with nontuberculous mycobacterial pulmonary disease exhibit reduced ATG7 expression in blood mononuclear cells and decreased ATG7 levels in necrotic lesions at disease sites. Mice lacking Atg7 in innate immune cells display elevated bacterial loads, excessive inflammation, mitochondrial damage, and multiple forms of cell death in the lungs, including pyroptosis, necrosis, and apoptosis. Notably, neutrophil infiltration in the lungs of these mice plays a key role in driving exacerbated inflammation and gasdermin E-associated cell death, which precede bacterial overgrowth. In vitro, Atg7-deficient macrophages exhibit impaired antimicrobial responses and reduced phagolysosomal fusion, but only modest increases in inflammation and cell death. These findings underscore the critical role of ATG7 in innate immune cells in orchestrating an effective host defense against nontuberculous mycobacterial lung infection by mitigating neutrophil-driven pathological inflammation and associated cell death.

PURPOSE OF THE REPORT:The usefulness of brain 18 F-FDG PET/CT in primary central nervous system lymphoma (PCNSL) remains underexplored. This study investigated whether early metabolic responses in interim brain FDG PET/CT serve as a prognostic indicator of PCNSL treatment outcomes. PATIENTS AND METHODS:This prospective study included 53 patients with PCNSL who underwent a high-dose methotrexate-based treatment. Brain FDG PET was performed at diagnosis (baseline PET) and after induction chemotherapy (interim PET), assessing interim PET parameters such as the highest maximum standardized uptake value (hSUV max ), sum of SUV max (sumSUV max ), highest tumor-to-normal ratio (hTNR max ), sum of TNR max (sumTNR max ), highest metabolic tumor volume (MTV) (hMTV), and sum of MTV (sumMTV) across all PET-positive lesions. RESULTS:High interim hTNR max (hazards ratio: 9.76, 95% confidence interval: 1.90-50.11, P = 0.01) was an independently significant predictor of poor progression-free survival in multivariate analysis. Patients with low interim hTNR max (≤1.0) had a significantly longer median progression-free survival than those with high interim hTNR max (>1.0) (25.0 vs 3.6 months, P < 0.001). Incorporating interim MRI-based clinical response assessments and hTNR max allowed the classification of partial response subgroups with markedly different prognoses ( P < 0.001). High interim hTNR max (hazards ratio: 2.76, 95% confidence interval: 1.39-5.48, P = 0.004) was an independently significant predictor of poor overall survival in multivariate analysis. CONCLUSIONS:The hTNR max measurement from interim brain FDG PET scans emerges as an important prognostic marker in PCNSL. These findings underscore the potential of interim FDG PET evaluations to refine response assessments and inform tailored therapeutic strategies.

Immunotherapy with checkpoint blockade has shown remarkable efficacy in many patients with a variety of different types of cancer. However, the majority of patients with cancer have yet to benefit from this revolutionary therapy. Studies have shown that checkpoint blockade works best against immune-inflamed tumors characterized by the presence of tumor-infiltrating lymphocytes (TILs). In this review, we summarize studies using live tumor-targeting bacteria to treat cancer and describe various strategies to engineer the tumor-targeting bacteria for maximized immunoregulatory effects. We propose that tumor-localized infections by such engineered bacteria can create an immune microenvironment in favor of a more effective antitumor immunity with or without other therapies, such as immune checkpoint blockade (ICB). Finally, we will briefly outline some exemplary oncology clinical trials involving ICB plus live therapeutic bacteria, with a focus on their ability to modulate antitumor immune responses.

Radiotherapy (RT) triggers immunogenic cell death (ICD). L-ASNase, which catalyzes the conversion of asparagine (Asn), thereby depleting it, is used in the treatment of blood cancers. In previous work, we showed that CRT3LP and CRT4LP, PASylated L-ASNases conjugated to the calreticulin (CRT) -specific monobodies CRT3 and CRT4, increase the efficacy of ICD-inducing chemotherapy. Here, we assessed their efficacy in tumor -bearing mice treated with RT. Methods: Monobody binding was evaluated by in silico molecular docking analysis. The expression and cellular localization of ecto-CRT were assessed by confocal imaging and flow cytometry. The antitumor effect and the roles of CRT3LP and CRT4LP in irradiation (IR)-induced ICD in tumors were analyzed by ELISA, immunohistochemistry, and immune analysis methods. Results: Molecular docking analysis showed that CRT3 and CRT4 monobodies were stably bound to CRT. Exposure to 10 Gy IR decreased the viability of CT -26 and MC -38 tumor cells in a time -dependent manner until 72 h, and increased the expression of the ICD marker ecto-CRT (CRT exposed on the cell surface) and the immune checkpoint marker PD -L1 until 48 h. IR enhanced the cytotoxicity of CRT3LP and CRT4LP in CT -26 and MC -38 tumor cells, and increased reactive oxygen species (ROS) levels. In mice bearing CT -26 and MC -38 subcutaneous tumors treated with 6 Gy IR, Rluc8-conjugated CRT -specific monobodies (CRT3-Rluc8 and CRT4-Rluc8) specifically targeted tumor tissues, and CRT3LP and CRT4LP increased total ROS levels in tumor tissues, thereby enhancing the antitumor efficacy of RT. Tumor tissues from these mice showed increased mature dendritic, CD4+ T, and CD8+ T cells and pro -inflammatory cytokines (IFN gamma and TNF alpha) and decreased regulatory T cells, and the expression of tumor cell proliferation markers (Ki67 and CD31) was downregulated. These data indicate that the combination of IR and CRT -targeting L-ASNases activated and reprogramed the immune system of the tumor microenvironment. Consistent with these data, an immune checkpoint inhibitor (anti -PD -L1 antibody) markedly increased the therapeutic efficacy of combined IR and CRT -targeting L-ASNases. Conclusion: CRT -specific L-ASNases are useful as additive drug candidates in tumors treated with RT, and combination treatment with anti -PD -L1 antibody increases their therapeutic efficacy.

A major obstacle to targeted cancer therapy is identifying suitable targets that are specifically and abundantly expressed by solid tumors. Certain bacterial strains selectively colonize solid tumors and can deliver genetically encoded cargo molecules to the tumor cells. Here, we engineered bacteria to express monomeric streptavidin (mSA) in tumors, and developed a novel tumor pre-targeting system by visualizing the presence of tumor-associated mSA using a biotinylated imaging probe. We constructed a plasmid expressing mSA fused to maltose-binding protein and optimized the ribosome binding site sequence to increase solubility and expression levels. E. coli MG1655 was transformed with the recombinant plasmid, expression of which is driven by the pBAD promotor. Expression of mSA was induced by L-arabinose 4 days after injection of bacteria into mice bearing CT26 mouse colon carcinoma cells. Selective accumulation of mSA in tumor tissues was visualized by optical imaging after administration of a biotinylated fluorescent dye. Counting of viable bacterial cells was also performed. Compared with a conventional system, the novel expression system resulted in significantly higher expression of mSA and sustained binding to biotin. Imaging signals in tumor tissues were significantly stronger in the mSA-expressing group than in non-expressing group (P = 0.0005). Furthermore, the fluorescent signal in tumor tissues became detectable again after multiple inductions with L-arabinose. The bacterial counts in tumor tissues showed no significant differences between conditions with and without L-arabinose (P = 0.45). Western blot analysis of tumor tissues confirmed expression and binding of mSA to biotin. We successfully engineered tumor-targeting bacteria carrying a recombinant plasmid expressing mSA, which was targeted to, and expressed in, tumor tissues. These data demonstrate the potential of this novel tumor pre-targeting system when combined with biotinylated imaging probes or therapeutic agents.

Immunotherapy has revolutionized the treatment of cancer but continues to be constrained by limited response rates, acquired resistance, toxicities and high costs, which necessitates the development of new, innovative strategies. The discovery of a connection between the human microbiota and cancer dates back 4,000 years, when local infection was observed to result in tumour eradication in some individuals. However, the true oncological relevance of the intratumoural microbiota was not recognized until the turn of the twentieth century. The intratumoural microbiota can have pivotal roles in both the pathogenesis and treatment of cancer. In particular, intratumoural bacteria can either promote or inhibit cancer growth via remodelling of the tumour microenvironment. Over the past two decades, remarkable progress has been made preclinically in engineering bacteria as agents for cancer immunotherapy; some of these bacterial products have successfully reached the clinical stages of development. In this Review, we discuss the characteristics of intratumoural bacteria and their intricate interactions with the tumour microenvironment. We also describe the many strategies used to engineer bacteria for use in the treatment of cancer, summarizing contemporary data from completed and ongoing clinical trials. The work described herein highlights the potential of bacteria to transform the landscape of cancer therapy, bridging ancient wisdom with modern scientific innovation. Increasing evidence indicates that intratumoural bacteria can have crucial roles in both the pathogenesis and treatment of cancer. In this Review, the authors discuss the characteristics of intratumoural bacteria and the emerging understanding of their tumour-promoting and antitumour activities. They also describe a range of innovative strategies that are being used to engineer bacteria for use in the treatment of cancer and summarize clinical trials of various bacteria-mediated cancer immunotherapies. Intratumoural bacteria interact with cancer cells and components of the tumour microenvironment in complex ways, which can either promote or suppress cancer. The effects depend on the bacterial species and the specific context of the tumour and the immune system.Bacteria-mediated cancer immunotherapies (BCITs) can induce tumour regression by disrupting cell metabolism, inducing apoptosis, delivering therapeutic agents and enhancing the anticancer immune response.Emerging BCIT strategies use advanced genetic engineering for precise gene regulation and bacterial surface modification, alongside the development of biohybrid microrobots, to effectively and selectively target tumours and deliver therapeutic agents.Clinical trials are exploring the use of bacteria in the treatment of cancer, including the use of modified bacterial strains and faecal microbiota transplantation to improve patient responses to immunotherapy, with a focus on safety, efficacy and optimal administration methods.Challenges in BCIT include deciphering the mechanisms of action, managing adverse effects, determining optimal doses, ensuring sterility and safety of the bacterial product, and overcoming regulatory barriers. However, ongoing research is laying the groundwork for incorporating BCIT into oncology practice.

Background/Aim: Colorectal cancer (CRC) is the third most common cancer worldwide, and is second only to lung cancer with respect to cancer -related deaths. Noninvasive molecular imaging using established markers is a new emerging method to diagnose CRC. The human ephrin receptor family type -A 2 (hEPHA2) oncoprotein is overexpressed at the early, but not late, stages of CRC. Previously, we reported development of an E1 monobody that is specific for hEPHA2-expressing cancer cells both in vitro and in vivo. Herein, we investigated the ability of the E1 monobody to detect hEPHA2 expressing colorectal tumors in a mouse model, as well as in CRC tissue. Materials and Methods: The expression of hEPHA2 on the surface of CRC cells was analyzed by western blotting and flow cytometry. The targeting efficacy of the E1 monobody for CRC cells was examined by flow cytometry, and immunofluorescence staining. E1 conjugated to the Renilla luciferase variant 8 (Rluc8) reporter protein was used for in vivo imaging in mice. Additionally, an enhanced green fluorescence protein (EGFP) conjugated E1 monobody was used to check the ability of the E1 monobody to target CRC tissue. Results: The E1 monobody bound efficiently to hEPHA2-expressing CRC cell lines, and E1 conjugated to the Rluc8 reporter protein targeted tumor tissues in mice transplanted with HCT116 CRC tumor cells. Finally, E1EGFP stained tumor tissues from human CRC patients, showing a pattern similar to that of an anti-hEPHA2 antibody. Conclusion: The E1 monobody has utility as an EPHA2 targeting agent for the detection of CRC.

Bacteria are ideal anticancer agents and carriers due to their unique capabilities that are convenient in genetic manipulation, tumor-specific targeting, and deep-tissue penetration. However, the specific molecular mechanisms of bacteria-mediated cancer therapy (BMCT) have not been clarified. In this study, we found that TLR4 signaling pathway is critical for Salmonella-mediated tumor targeting, tumor suppression, and liver and spleen protection. TLR4 knockout in mice decreased the levels of cytokines and chemokines, such as S100a8, S100a9, TNF-α, and IL-1β, in tumor microenvironments (TMEs) after Salmonella treatment, which inhibited tumor cell death and nutrient release, led to reduced bacterial contents in tumors and attenuated antitumor efficacy in a negative feedback manner. Importantly, we found that S100a8 and S100a9 played a leading role in Salmonella-mediated cancer therapy (SMCT). The antitumor efficacy was abrogated and liver damage was prominent when blocked with a specific inhibitor. These findings elucidated the mechanism of Salmonella-mediated tumor targeting, suppression, and host antibacterial defense, providing insights into clinical cancer therapeutics.

Addressing age-related immunological defects through therapeutic interventions is essential for healthy aging, as the immune system plays a crucial role in controlling infections, malignancies, and in supporting tissue homeostasis and repair. In our study, we show that stimulating toll-like receptor 5 (TLR5) via mucosal delivery of a flagellin-containing fusion protein effectively extends the lifespan and enhances the healthspan of mice of both sexes. This enhancement in healthspan is evidenced by diminished hair loss and ocular lens opacity, increased bone mineral density, improved stem cell activity, delayed thymic involution, heightened cognitive capacity, and the prevention of pulmonary lung fibrosis. Additionally, this fusion protein boosts intestinal mucosal integrity by augmenting the surface expression of TLR5 in a certain subset of dendritic cells and increasing interleukin-22 (IL-22) secretion. In this work, we present observations that underscore the benefits of TLR5-dependent stimulation in the mucosal compartment, suggesting a viable strategy for enhancing longevity and healthspan.

Synergistic combinations of immunotherapeutic agents can improve the performance of anti-cancer therapies but may lead to immune-mediated adverse effects. These side-effects can be overcome by using a tumor-specific delivery system. Here, we report a method of targeted immunotherapy using an attenuated Salmonella typhimurium (SAM-FC) engineered to release dual payloads: cytolysin A (ClyA), a cytolytic anti-cancer agent, and Vibrio vulnificus flagellin B (FlaB), a potent inducer of anti-tumor innate immunity. Localized secretion of ClyA from SAM-FC induces immunogenic cancer cell death and promotes release of tumor-specific antigens and damage-associated molecular patterns, which establish long-term antitumor memory. Localized secretion of FlaB promotes phenotypic and functional remodeling of intratumoral macrophages that markedly inhibits tumor metastasis in mice bearing tumors of mouse and human origin. Both primary and metastatic tumors from bacteria-treated female mice are characterized by massive infiltration of anti-tumorigenic innate immune cells and activated tumor-specific effector/memory T cells; however, the percentage of immunosuppressive cells is low. Here, we show that SAM-FC induces functional reprogramming of the tumor immune microenvironment by activating both the innate and adaptive arms of the immune system and can be used for targeted delivery of multiple immunotherapeutic payloads for the establishment of potent and long-lasting antitumor immunity.

The use of appropriately designed immunotherapeutic bacteria is an appealing approach to tumor therapy because the bacteria specifically target tumor tissue and deliver therapeutic payloads. The present study describes the engineering of an attenuated strain of Salmonella typhimurium deficient in ppGpp biosynthesis (SAM) that could secrete Vibrio vulnificus flagellin B (FlaB) conjugated to human (hIL15/FlaB) and mouse (mIL15/FlaB) interleukin-15 proteins in the presence of L-arabinose (L-ara). These strains, named SAMphIF and SAMpmIF, respectively, secreted fusion proteins that retained bioactivity of both FlaB and IL15. SAMphIF and SAMpmIF inhibited the growth of MC38 and CT26 subcutaneous (sc) tumors in mice and increased mouse survival rate more efficiently than SAM expressing FlaB alone (SAMpFlaB) or IL15 alone (SAMpmIL15 and SAMphIL15), although SAMpmIF had slightly greater antitumor activity than SAMphIF. The mice treated with these bacteria showed enhanced macrophage phenotype shift, from M2-like to M1-like, as well as greater proliferation and activation of CD4+ T, CD8+ T, NK, and NKT cells in tumor tissues. After tumor eradication by these bacteria, ≥50% of the mice show no evidence of tumor recurrence upon rechallenge with the same tumor cells, indicating that they had acquired long-term immune memory. Treatment of mice of 4T1 and B16F10 highly malignant sc tumors with a combination of these bacteria and an immune checkpoint inhibitor, anti-PD-L1 antibody, significantly suppressed tumor metastasis and increased mouse survival rate. Taken together, these findings suggest that SAM secreting IL15/FlaB is a novel therapeutic candidate for bacterial-mediated cancer immunotherapy and that its antitumor activity is enhanced by combination with anti-PD-L1 antibody.

Intracranial sarcoma is an uncommon aggressive cancer with a poor prognosis and a high recurrence rate. Although postoperative adjuvant radiotherapy (RT) is the most recommended treatment strategy, it does not significantly improve survival rates. In this study, we used an attenuated Salmonella typhimurium strain engineered to secrete Vibrio vulnificus flagellin B (SLpFlaB) as an immunotherapy to assist with the antitumor effects of RT on intracranial sarcoma. In vitro, the expression of γH2AX and cleaved caspase-3 was analyzed by Western blot. In vivo detection of SLpFlaB colonization time in tumors was measured using an in vivo imaging system (IVIS). Tumor growth delay and elimination were demonstrated in an intracranial mouse model, and the distribution of macrophages, M1 macrophages, and CD8+ cells after treatment was measured using FACS analysis. Our findings in vitro suggest that combination therapy increases S-180 radiosensitivity, the expression of DNA double-strand breaks, and programmed cell death. In vivo, combination treatment causes intracranial sarcoma to be eliminated without tumor recurrence and redistribution of immune cells in the brain, with data showing the enhanced migration and infiltration of CD8+ T cells and macrophages, and an increased proportion of M1 macrophage polarization. Compared to RT alone, the combination therapy enhanced the radiosensitivity of S-180 cells, promoted the recruitment of immune cells at the tumor site, and prevented tumor recurrence. This combination therapy may provide a new strategy for treating intracranial sarcomas.

Introduction: Despite the prognostic significance of 18F-fluorodeoxyglucose (FDG)-positron emission tomography-computed tomography (PET/CT) assessment has important implications on determining the response-adapted therapy in patients with peripheral T-cell lymphomas (PTCLs), an optimal timing of the use and clinical application of PET/CT-based response are still up in the air. The aim of this study was to explore the prognostic impact of sequential 18F-FDG PET/CT analysis in patients with newly diagnosed PTCLs who treated with frontline anthracycline-based chemotherapy. Methods: Between February 2006 and September 2022, 143 patients with newly diagnosed PTCLs were included. All patients were treated with 6 cycles of anthracycline-containing chemotherapy. Sequential 18F-FDG PET/CT were obtained at the time of diagnosis, after three cycles of chemotherapy and finally at the end of chemotherapy. Baseline total metabolic tumor volume (TMTV) was computed with the sum of SUV2.5 threshold method, and the PET/CT response were assessed using the five-point scale (5-PS) of Deauville criteria. Results: Baseline MTV could be calculated in 126 patients, and the cut-off value of TMTV according to ROC analysis was 457.0 cm3 (Sensitivity 45.0%, specificity 74.0%). With a median follow-up of 52.0 months (range 3.8–153.9 months), patients with high TMTV more than cut-off value had inferior PFS and OS than those with low TMTV (PFS, 9.8 months vs. 26.5 months, HR 1.600, 95% CI 1.010–2.671, p = 0.043; OS, 18.9 months vs. 71.2 months, HR 2.135, 95% CI 1.261–3.615, p = 0.004, Figure 1A, B). Interim 18F-FDG PET/CT assessment was available in all 143 patients. When patients were categorized with three subgroups as response with grade 1, grade 2 and 3, and grade 4–5, PFS and OS showed significant difference according to interim visual assessment (PFS, 120.7 months vs. 34.1 months vs. 5.1 months, p < 0.001; OS, not reached vs. 61.1 months vs. 12.1 months, p < 0.001, Figure 1C, D), respectively. Among 77 patients who were assessed as grade 2 or 3 in interim PET/CT analysis, 19 patients (26.3%) turned over a remnant tumor metabolism or progressed at final PET response assessment. Moreover, the outcome of patients with interim grade 2 or 3 showed the significant differences based on the final achievement of complete metabolic response or not in PFS and OS (PFS, 59.9 months vs. 7.2 months, HR 4.754, 95% CI 2.267–9.971, p < 0.001; OS, not reached vs. 24.0 months, HR 3.706, 95% CI 1.592–8.630, p = 0.001), respectively. Keywords: aggressive T-cell non-Hodgkin lymphoma, diagnostic and prognostic biomarkers No conflicts of interests pertinent to the abstract.