Microsatellite instability-low/microsatellite stable (MSI-L/MSS) colorectal cancer (CRC) exhibits limited responsiveness to immune checkpoint inhibitors due to low tumor mutational burden and insufficient neoantigen generation. Carboxyl-terminal modulator protein (CTMP) is a potential regulatory molecule that may reshape tumor immunogenicity and metabolic patterns, yet its mechanisms in MSI-L/MSS CRC remain poorly understood. We systematically investigated CTMP function by integrating clinical sample analysis (GEO database, n = 71 paired tissue microarray, and pretreatment specimens from 11 refractory patients receiving anti-PD-1 plus fruquintinib), in vitro experiments (MSS CRC cells with CTMP knockdown/overexpression, assessed for proliferation, mitochondrial function, lipid metabolism, AKT/PD-L1 signaling, and MHC-I/HLA-B expression), proteomic screening (immunoprecipitation-mass spectrometry to identify CTMP-interacting proteins), structural validation (co-immunoprecipitation, AlphaFold Multimer, GST pulldown with truncation/point mutations), and in vivo studies (immunocompetent BALB/c mice with CT26 syngeneic tumors). High CTMP expression and low HLA-B expression were significantly associated with shortened overall survival in patients with MSI-L/MSS colon adenocarcinoma, as well as with progressive disease in an anti-PD-1/fruquintinib resistance cohort. Mechanistically, CTMP orchestrated an immunosuppressive tumor microenvironment by sustaining AKT/PD L1 signaling, suppressing HLA B expression, and promoting fatty acid metabolism. Proteomic screening identified a previously unreported high-affinity interaction between CTMP and REV7, which facilitated CDK1 mediated G2/M progression and further repressed HLA B expression. CTMP knockdown or REV7 overexpression diminished CDK1 activity, induced G2/M phase arrest, and restored HLA B expression in a cGAS signaling-relevant manner, while also reversing the IFN γ enhanced CTMP–REV7 interaction. In immunocompetent murine models, CTMP knockdown or REV7 overexpression suppressed tumor growth, upregulated HLA B expression, and enhanced intratumoral CD8⁺ T cell infiltration. Moreover, REV7 overexpression synergized with IFN-γ to promote the release of chemokines (CXCL9, CXCL10, TNF α), leading to marked tumor regression in CTMP-KD tumors. We delineate that CTMP drives immune evasion in MSI-L/MSS CRC through a novel CTMP–REV7–CDK1 axis that couples metabolic reprogramming, cell cycle control, and MHC-I antigen presentation, with AKT signaling serving as a critical crosstalk node. These findings implicate this integrated axis as a therapeutic target to restore tumor immunogenicity and overcome immunotherapy resistance in immunologically “cold” MSI-L/MSS colorectal cancer.

PURPOSE:The purpose of this study was to explore the factors affecting the stability of deep inspiration breath-hold for left-sided breast cancer radiotherapy and provide directional suggestions for clinicians to consider whether patients with left-sided breast cancer were fit for this technique. MATERIAL AND METHODS:Using optical body surface monitoring system, 100 patients with left-sided breast cancer were trained for deep inspiration breath-hold before computed tomography positioning. The patients' age, height, weight, vital capacity, type of surgery (modified radical or breast-conserving operation) were recorded. According to the duration and fluctuation of each inspiration, the patients were divided into five categories. The statistical methods of Spearman and Kendall were used to calculate correlation coefficients, and the p values of these factors and breath-holding stability grades were calculated using the Spss software; the correlation heat map was drawn by Origin software, reflecting which of the above factors had significant correlation with breath-holding stability and their correlation strength. RESULTS:Values of p inferior to 0.05 were obtained for vital capacity, body mass index, age and surgical method, and values of p greater than 0.05 were obtained for adjuvant chemotherapy and targeted treatment. According to the value of correlation coefficient and correlation heat map, the order of strength is vital capacity>body mass index>age>surgical method. CONCLUSION:The patient's age, vital capacity, body mass index and operation method significantly affect the stability of breath-holding. For breast cancer radiotherapy, clinicians can select patients by considering these factors related with the stability of holding their breath.

Tropomyosin receptor kinases (TRK) tyrosine kinase inhibitors (TKIs) have demonstrated marked efficacy in neurotrophic receptor tyrosine kinase (NTRK) fusion positive tumors. However, resistance inevitably develops. Eratrectinib (VC004) is a next-generation selective TRK TKI which can overcome drug resistance. In this phase 1 study, patients with locally advanced or metastatic solid tumors were enrolled in the dose-escalation part. A standard 3 + 3 design was adopted to sequentially assign patients at 25 mg twice daily (BID), 50 mg BID, 100 mg BID, and 200 mg BID dose levels of oral eratrectinib. After each dose had been established, we expanded specific dose cohorts in patients with NTRK fusion positive locally advanced or metastatic solid tumors to obtain adequate data for safety, pharmacokinetics (PK), and efficacy. The primary endpoints of this study were safety, maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D). Between December 4, 2020 and November 4, 2021, 16 patients were enrolled in the dose-escalation part and a dose of 100 mg BID was identified as MTD. Between May 8, 2021 and March 19, 2025, 75 patients were enrolled in the dose-expansion part at doses of eratrectinib 25 mg BID, 50 mg BID, and 75 mg BID. Treatment-emergent adverse events (TEAEs) occurred in 94.7

Conventional CD3-targeting bispecific T cell engagers (BiTEs) have shown limited efficacy in solid tumors, largely due to the highly immunosuppressive tumor microenvironment (TME) and systemic T cell activation-associated toxicity. To address this challenge, we developed a peptide-MHC class I-based T cell engager platform that selectively redirects a specific subset of CD8+ T cells to tumor cells. Using the model ovalbumin (OVA) system, we engineered fusion proteins comprising an OVA peptide-H-2Kᵇ complex linked to an anti-HER2 nanobody (OVA-αHER2), enabling simultaneous engagement of OVA-specific T cells and HER2-expressing tumor cells and inducing potent tumor cell killing in vitro. To overcome the immunosuppressive TME, we further combined a HER2-targeted IL-12 fusion protein with OVA-αHER2, achieving synergistic anti-tumor responses in a mouse B16-HER2 solid tumor model. This treatment enhanced both systemic and intratumoral OVA-specific CD8+ T cell responses, accompanied by increased IFN-γ production in the TME. Together, these findings establish a modular immunotherapy strategy that integrates recruitment of a specific CD8+ T cell subset with localized cytokine-mediated immune reprogramming, providing a potential approach for HER2-positive solid tumors.

3530 Background: Under suboptimal efficacy and safety of current third-line standard-of-care (SoC), several single-arm studies have demonstrated that anti-PD-(L)1 antibodies plus EGFR inhibitors with or without chemotherapy may be valuable for relapsed/refractory RAS/BRAF wild-type and microsatellite stable metastatic colorectal cancer (R/R RAS/BRAF WT and MSS mCRC). This study aimed to compare tislelizumab (anti-PD-1 antibody) plus cetuximab and irinotecan as third- or later-line therapy versus investigator-selected SoC for R/R RAS/BRAF WT and MSS mCRC. Methods: This was a randomized controlled, open-label, multicenter study (NCT05278351). Eligible patients were aged ≥18 years with histologically confirmed RAS/BRAF WT and MSS metastatic colorectal adenocarcinoma who failed ≥2 prior lines of systemic therapy. Patients were randomly assigned (2:1) to receive intravenous tislelizumab (200 mg) plus cetuximab (500 mg/m 2 ) and irinotecan (180 mg/m 2 ) on days 1 and 15 or investigator-selected SoC (fruquintinib, regorafenib, or TAS-102) in a 4-week cycle until disease progression, unacceptable toxicity, or other protocol-defined reasons. Primary end point was progression-free survival (PFS). Secondary end points included objective response rate, disease control rate, duration of response, overall survival, and safety. Results: Eighty-seven patients (median age, 62.0 years; 59 [67.8%] men) were enrolled between July 2022 and March 2024, randomized, and assessed for efficacy; one patient did not receive the triplet regimen and was removed from the safety population. With median follow-up of 26.1 months (95% confidence interval [CI]: 22.4-28.4) by data cutoff (June 30, 2025), median PFS was 4.4 months (95% CI, 3.8-6.6) in the tislelizumab-cetuximab-irinotecan group and 2.0 months (95% CI, 1.9-5.4) in the SoC group (Breslow-Gehan P =0.009). Landmark analysis at a cutoff point of 10 months showed a significantly extended PFS with tislelizumab plus cetuximab and irinotecan versus SoC (HR 0.37 [95% CI, 0.21-0.64]; p<0.001). Grade ≥3 treatment-related adverse events (TRAEs) occurred at comparable frequencies in the two groups (15.8% vs 17.2%). No TRAEs led to death. Conclusions: Tislelizumab plus cetuximab and irinotecan as third- or later-line therapy appeared feasible and safe for patients with R/R RAS/BRAF WT and MSS mCRC. Clinical trial information: NCT05278351 . Tislelizumab-cetuximab-irinotecan (n=58) SoC (n=29) Best response Complete response 0 0 Partial response 12 (20.7) 1 (3.4) Stable disease 32 (55.2) 12 (41.4) Disease progression 11 (19.0) 16 (55.2) Not evaluable 3 (5.2) 0 Objective response 12 (20.7) 1 (3.4) Disease control 44 (75.9) 13 (44.8) 6-month PFS rate, % (95% CI) 38.2 (27.3-53.5) 20.4 (9.6-43.7)

e15547 Background: Kirsten rat sarcoma (KRAS) mutations lead to aberrant activation of the RAS/RAF/MEK/ERK signaling pathway, promoting cell proliferation and metastasis, and are among the most common oncogenic mutations in colorectal cancer (CRC) patients. Frequent point mutations include G12D, G12V, and G13D. Patients with these mutations often have poor prognosis and exhibit drug resistance. Immunotherapy may become a potential treatment to improve the current status.Oncolytic virus vaccines are genetically engineered viruses targeting tumor-specific antigens, which enhance tumor cytotoxicity and immune responses. This study aims to initially construct an oncolytic virus vaccine targeting KRAS mutations and validate its preclinical efficacy, addressing the lack of treatment options for advanced colorectal cancer and improving the poor response of CRC to immunotherapy. Methods: Based on the wild-type herpes simplex virus HSV-1 (F strain), we constructed KRAS-mutant oncolytic virus vaccine(KR10) by incorporating the KRAS mutation gene(G12D, G12C,etc). KR11, with GFP inserted, and KR12, with Flu-MP inserted, were used as control groups. Western blot was applied to verify the success of the construction. CCK-8 assay were performed to assess the selective cytotoxic effects of KR10 on normal cells and tumor cells.A subcutaneous xenograft tumor model (CT26 colorectal cancer) in mice was developed to evaluate the anti-tumor efficacy of KR10 at different viral doses. Pharmacokinetic and pharmacological studies were then conducted in large animal models(crab-eating macaques). Results: The KR10 was engineered successfully. Cytotoxicity assays showed the selective killing of tumor cells and the safety of KR10 on normal cells. In the CT26 (KRAS -G12D) model, KR10 significantly reduced tumor size and volume compared to the control groups, with effects increasing with dose within a certain range.Furthermore, re-administration of KR10 in mice demonstrated sustained anti-tumor effects. For crab-eating macaques, intravenous and subcutaneous KR10 administration showed no signs of severe toxicity, death, or distress, and there were no significant abnormalities in any safety indicators. Pharmacokinetic studies revealed dose-dependent viral clearance with minimal drug accumulation, and limited viral shedding via the respiratory/digestive tracts. Immunological assays indicated mild immune activation, evidenced by elevated IgG and IgM levels and complement consumption. Conclusions: This study is a preclinical investigation of KRAS-mutant oncolytic virus vaccine for the treatment of metastatic colorectal cancer. It is the first to construct an oncolytic virus (KR10) targeting the G12D mutation on KRAS, with in vitro efficacy validation and animal experiments. The funding for this study was supported by the Shanghai Shenkang Project (No.SHDC2022CRT009).

240 Background: SDC2 gene encodes the transmembrane proteoglycan molecule Syndecan-2. Syndecan-2 protein affects the proliferation, migration and invasion of colorectal cancer cells by participating in the regulation of cell adhesion, tissue differentiation and angiogenesis. Plasma methylated SEPTIN9 gene has been shown to be a sensitive and specific biomarker for the detection of CRC, which is involved in apoptosis, pseudopod projection, tumor cell migration and invasion. The aim of this study is to validate the value of SDC2 and S9 gene methylation detection in the diagnosis and efficacy evaluation of CRC. Methods: A total of 102 patients were enrolled in the study. The methylation levels of fecal SDC2 gene and blood SEPTIN9 gene were detected by fluorescence PCR. The clinical diagnostic accuracy of SDC2 kit was evaluated by patients with benign gastrointestinal lesions, gastrointestinal tumors and healthy subjects. Combined detection of SDC2 and S9 to improve the detection rate of CRC. SDC2m levels were analyzed in 26 patients with partial remission or stable disease after palliative treatment and 32 patients with complete remission after radical surgery. Results: The detection rate of SDC2 in patients was 0.0% for UC and CD, 66.7% for AA and 60.0% for NA, 25.0% for HOP. For 8 healthy subjects with negative colonoscopies, the true negative rate was 100%. The detection rates of GC and EC were 50.0% and 0.0%, respectively. Data from 72 patients with CRC were evaluated, with a sensitivity of 89.1% (41/46,95%CI 0.798-0.985) for patients with untreated CRC. The sensitivity of SDC2 was 46.2% (12/26,95%CI 0.256-0.667) in patients with partial response or stable disease after palliative treatment. The difference was statistically significant (P < 0.001). The sensitivity of S9 for CRC detection was 88.2% (15/17, 95%CI 0.712-1.053). By two tests, 94.1%(16/17, 95%CI 0.816-1.066) of CRC cases could be detected.The sensitivity was 89.1% (41/46 95%CI 0.798-0.985) in untreated CRC and 46.2% (12/26 95%CI 0.256-0.667) in patients with PR and SD after chemotherapy/radiotherapy/targeted/immunotherapy. The difference rate of SDC2m between two groups was statistically significant (P < 0.001). Among 46 untreated patients with CRC, 32 patients with positive SDC2m underwent radical surgery, of which 30 CR patients turned SDC2m test negative after surgery. We found reduced SDC2m in stool from patients with clinical benefit (CR+PR+SD). Conclusions: Detection of SDC2m in untreated CRC patients has high sensitivity and has the potential to become a non-invasive diagnostic tool for CRC. Combination of S9 and fecal SDC2 could improve the detection rate of SDC2 in non-dominant population. The methylation level of SDC2 may be helpful for postoperative follow-up of CRC after radical surgery, prediction of recurrence, and monitoring the efficacy of a series of palliative treatments for CRC.

246 Background: Regimen of metastatic colon cancer (mCOAD) is moving towards combination of immune checkpoint inhibitors (ICBs) and targeted therapy, however ICBs are rarely effective in MSI-L metastatic colon cancers, limiting options for backline treatments, new targeted therapy is on demand to improve immunogenicity of MSI-L mCOAD. As targeting fatty acid metabolism or cell cycle has shown potential in improving the efficacy of ICBs, our team focused on CTMP, a thioesterase (ACOT) family member, mainly modulates fatty acid β oxidation, meanwhile it binds to phosphorylation sites of AKT thus intervenes cell cycle, currently its role on immunogenicity of COAD is not clear. Methods: Correlation between CTMP and OS in MSI-L colon cancer patients was assessed by KM plotter in GEO database.11 Clinical samples of MSI-L colon cancer, who received a third-line treatment regimen of anti-PD-1 and fruquintinib, were collected then applied in immunofluorescence and western blot analyses to evaluate CTMP and MHC-I expression. In vitro, Lentiviral transfection of targeted genes were stably established,then applied in RNA-seq and metabolic assays. Proteomic analysis and co-IP were applied to explore CTMP-modulating pathway. In vitro, IFNγ was intratumorally injected. Results: KM curve showed CTMP was negatively correlated with OS in MSI-L COAD in GEO database. In clinical samples, lower CTMP expression and higher MHC-I expression were observed in partial response (PR) than progressive disease (PD) group. In vitro, CTMP-OE reduced MHC-I, increased AKT phosphorylation and immune checkpoints (PD-L1, IDO-1), promoted clone formation. Seahorse assay showed increased capacity of glycolysis and oxidative phosphorylation in CTMP-OE than vector. RNA-seq showed CTMP-OE reduced MHC-I augmentation under IFN-γ treatment, meanwhile glucose metabolism genes, ACOT family ,immune checkpoints were also up-regulated, indicating ACOT family related metabolism promotion and immunogenicity suppression of COAD. Proteomic analysis and co-IP assay indicated CTMP interacts REV7, a key mitotic regulatory protein. Enzyme activity assay showed REV7 negatively regulates CDK1. Furthermore, REV7-OE alone is capable to induce MHC I augmentation and G2 arrest, accordingly CTMP-KD enhanced REV7's negative modulation on CDK1,contributing to G2 arrest, that also augmented MHC I . In homologous mice tumor-bearing model, tumor shrinkage was observed in CTMP-KD/ REV7-OE group. CTMP-KD/ REV7-OE increases MHC I expression,CD8+ T cell infiltration under IFN γ intra-tumoral injection. Conclusions: In summary, our studies suggested that CTMP regulates the metabolism of colorectal cancer and intervenes MHC-I molecules expression, and targeting CTMP is potential in suppressing tumor cell cycle and promoting immunogenicity through its modulation on REV7.

e15131 Background: IL-6 has been found to be highly expressed in a wide range of cancer species and is thought to be associated with poor prognosis and treatment resistance. IL-6 inhibitors like tocilizumab are used to treat inflammatory diseases and cytokine release syndrome. We hope to find effective drugs in traditional Chinese medicine to improve patients' conditions with oral taking, lower price and longer lasting effect. BDL is a formula made up of 7 traditional Chinese medicines and has been used for years to boost immunity and anti-inflammatory treatment. We have previously confirmed that BDL can inhibit IL-6 in tumor cells in vitro and animal experiments. This study aims to clarify the toxicological effect of BDL granules and explore the effectiveness and safety in reducing the level of IL-6 in cancer patients in clinical practice. Methods: The content and active ingredients of BDL granules were determined by high performance liquid chromatography (HPLC). SD rats were gastric perfused with BDL, single dose toxicity study and 4 weeks repeat dose toxicity study were performed respectively. General behavioral, hematological and blood biochemical parameters and histopathology were observed and recorded. The clinical study included 25 cancer patients with elevated IL-6 who were given BDL granules orally, 48g per day, twice for 7 consecutive days. The changes of serum IL-6 levels were detected before and after medication. Results: The traditional Chinese medicines used to prepare BDL granules include Rhubarb, Radix Isatidis and Cornus officinalis. The quality of the main active ingredients such as emodin, chrysophanol, (R.S)–geichenol, maggianin were analyzed and controlled according to the requirements of Chinese Pharmacopoeia. BDL was found non-toxic up to 24g/kg in single-dose study, and the safe dose of BDL for rats after 4 weeks was 12g/kg, which was much higher than the applied concentration on human (0.8g/kg). All the animals survived to the end of the experiment, gross pathology, blood chemistry, hematology and histopathology were within normal ranges. Among the 25 enrolled patients, 76% had lower IL-6 levels after medication than before, and the difference was statistically significant (* P < 0.05). Treatment-related adverse reactions included abdominal pain (4%) and diarrhea (12%), among which 1 case of grade 3 diarrhea was relieved after symptomatic treatment. No hematological and biochemical toxicity was found. Conclusions: BDL granules meet China's national good manufacturing practices (GMP) standards and reduce IL-6 levels in cancer patients, which is safe and effective, may be considered for the treatment of tumor-related inflammation, reduce the inflammatory side effects caused by immunotherapy and improve the prognosis of tumor patients in combination with other drugs. Further clinical research is still needed.

e24038 Background: Chemotherapy is one of the important methods of anti-tumor treatment at present. It brings disease remission along with various adverse events. Peripheral neurotoxicity is one of the adverse events caused by chemotherapy and is usually caused by drugs such as oxaliplatin or paclitaxel. Peripheral neuropathy is not fatal disease, but it seriously affects the patient's quality of life. Methods: In this study, we tried the neurotic electrophysiologic method by way of PainVision system to evaluate the current of perception threshold (CPT) of patients who were about to receive or were receiving chemotherapy with oxaliplatin or paclitaxel. The detection site is the inner side of the forearm , or the limbs where numbness is obvious. During the subsequent treatment, the CPT levels were continuously monitored and the CPT levels of the same detection site were compared. Patients with concurrent central nervous system lesions were excluded. Results: The results showed that among the 78 patients who participated in the monitoring, 36 patients did not endure obvious neurotoxic symptoms such as numbness or pain, and their CPT levels did not change significantly. The remaining 42 patients felt varying degrees of peripheral neurotoxicity, manifested as numbness or pain in the hands and feet, and poor activity. Among them, 20 patients experienced gradually worsened symptoms following the increased cycles of treatments, and the CPT level also increased. Among them, 14 patients changed treatment regimens due to disease progression and discontinued the use of relevant drugs. The CPT level no longer increased, but it did not decrease significantly in the short term.The patients who discontinued the related drugs for more than 6 months showed a decrease of CPT but no statistical significance. Conclusions: The PainVision system is designed to carry out quantitatively assessment of pain. This study used it to quantitatively assess peripheral neuropathy caused by chemotherapy drugs, which initially reflected the feasibility of clinical application and provided a quantitative basis for assessment of lesion severity and treatment efficacy. The CPT level of patients with or without peripheral neuropathy symptoms. Peripheral Neuropathy Symptoms N CPT (mean ± sd , μA) p value No 36 Before Therapy 17.65 ± 4.58 After Therapy 18.80 ± 3.13 p =0.074 Yes 42 N/A 25.73 ± 10.64 p <0.01 * Washout Period N/A 28 N/A 26.99 ± 11.73 < 6 Months 9 N/A 24.4 ± 7.89 p= 0.534 * > 6 Months 5 N/A 19.65±6.90 p= 0.348 * * Compared with the patients after therapy but without symptoms. ** Compared with the patients still receiving related drugs.

Malignant luminal alimentary tract tumor chemotherapy remains a great challenge at present due to risks and toxicities associated with current chemodrugs, as well as the potential for treatment resistance. Layered double hydroxide (LDH)/ethylenediamine tetraacetic acid (EDTA), such a tumor disaggregation-based treatment reagent for alimentary tract cancers was assessed in six patients bearing luminal tumors. The aim of this study was to evaluate the bio-safety and efficacy of LDH/EDTA for treating luminal alimentary tract tumors with high malignance. Two patients with colorectal cancer received intestinal perfusion of LDH/EDTA by colonoscopy every week for 6 weeks, and four patients with esophagus tumors received oral administration of LDH/EDTA for at least 1 month. The efficacy of LDH/EDTA were evaluated by determining tumor size reductions through contrast-enhanced CT imaging. Tumor cell dissociation was evaluated by flow cytometry to validate the tumor disaggregation. The colorectal cancer patients presented 33.3 www.chictr.org.cn (ChiCTR2200061587, ChiCTR2200065010).

Malignant mesothelioma (MM) is an aggressive and currently incurable cancer with limited therapeutic options. Due to the high expression of mesothelin in this cancer, anti-PD-1 nanobody-armored mesothelin-targeting CAR-T (NAC-T) cells are developed. Based on the enhanced anti-tumor activity observed in preclinical in vitro and in vivo studies, a first-in-human clinical trial is initiated. Eleven patients with malignant mesothelioma who have progressed after standard therapies receive intravenous infusions of 5-20 × 106 per kg NAC-T cells following lymphodepletion. The treatment is well tolerated, with no dose-limiting toxicity observed. The overall response rate is 63.6%, including one complete response, and the disease control rate is 100%. The median progression-free survival is 5.0 months, and the median overall survival is 25.6 months. Moreover, T cell receptor and single-cell sequencing analyses in patients with varying responses revealed specific clonal expansion of T cell subtypes and enhanced reactivity to tumor-associated antigens. These findings suggest that NAC-T cell therapy represents a promising therapeutic strategy for patients with malignant mesothelioma.

Pancreatic cancer is difficult to manage owing to the challenges involved in its treatment and nursing. This study aimed to clarify the roles and mechanisms of action of Poly (A)-binding protein cytoplasmic 1 (PABPC1) on pancreatic cancer. The expression of PABPC1 in pancreatic cancer tissues and cell lines was detected using RT-qPCR and western blotting. The effects of PABPC1 on proliferation, apoptosis, epithelial-mesenchymal transition (EMT), and the PI3K/AKT signaling pathway in pancreatic cancer cells were further investigated using MTT assays, flow cytometry, and western blotting. The expression of PABPC1 was significantly upregulated in pancreatic cancer tissues and cells, whereas PABPC1 downregulation inhibited pancreatic cancer cell proliferation, induced apoptosis, decreased the expression of EMT-associated proteins, and exerted a regulatory effect by inhibiting the PI3K/AKT signaling pathway. In addition, the findings indicated that PABPC1 over-expression significantly promoted pancreatic cancer cell proliferation, inhibited apoptosis, decreased the expression of E-cadherin, enhanced N-cadherin expression, and activating the PI3K/AKT signaling pathway. PABPC1 silencing significantly inhibited proliferation and EMT and induced apoptosis in pancreatic cancer cells. These findings provide novel insights into the role of PABPC1 in the development of pancreatic cancer.

The RIG-I/MAVS signaling stimulates anti-tumor immunity by triggering the production of inflammatory cytokines. Activation of MAVS induced by viral RNA and RIG-I binding is critical in this pathway. However, the molecular mechanism underlying the regulation of MAVS activity and its function in anti-tumor immunity is not fully understood. Here, we report that the ubiquitin-specific protease 35 (USP35) negatively regulates the MAVS signaling. Mechanistically, USP35 interacts with MAVS and removes its K63-linked polyubiquitin chains, thereby inhibiting viral-induced MAVS-TBK1-IRF3 activation and downstream inflammatory gene expression. Importantly, depletion of USP35 significantly enhances the anti-tumor immunity and synergizes with oncolytic virotherapy to suppress xenograft tumor growth of melanoma cells. Thus, our study identifies USP35 as a negative regulator of MAVS signaling, representing a potential immunosuppressive factor in cutaneous melanoma.

Currently approved human epidermal growth factor receptor 2 (HER2)-targeted antibody therapies are largely derived from trastuzumab, including trastuzumab-chemotherapy combinations, fixed-dose trastuzumab-pertuzumab combinations, and trastuzumab antibody-drug conjugates. To expand the options, bispecific antibodies, which may better utilize the benefits of combination therapy, are being developed. Among them, biparatopic antibodies (bpAbs) have shown improved efficacy compared to monoclonal antibody (mAb) combinations in HER2-positive patients. BpAbs bind two independent epitopes on the same antigen, which allows fine-tuning of mechanisms of action, including enhancement of on-target specificity and induction of strong antigen clustering due to the unique binding mode. To fully utilize the potential of bpAbs for anti-HER2 drug development, it is crucial to consider formats that offer stability and high-yield production, along with a functional balance between the two epitopes. In this study, we rationally designed a bpAb, KJ015, that shares a common light chain with two Fab arms and exhibits functionally balanced high affinity for two HER2 non-overlapping epitopes. KJ015 demonstrated high-expression titers over 7 g/L and stable physicochemical properties at elevated concentrations, facilitating subcutaneous administration with hyaluronidase. Moreover, KJ015 maintained comparable antibody-dependent cytotoxicity, phagocytosis, and complement-dependent cytotoxicity with trastuzumab plus pertuzumab. It exhibited enhanced synergy when administered subcutaneously with hyaluronidase and anti-PD-1 mAb in a mouse tumor model, suggesting promising clinical prospects for this combination.

2635 Background: Immune checkpoint inhibitors (ICIs) have shown significant efficacy in metastatic gastric cancer, but some patients may not respond to them because of immune resistance. Recombinant Human Adenovirus Type 5 (H101), the world’s first oncolytic virus antitumor drug in China, can induce cell death, expose tumor antigens, provide adjuvants for anti-tumor immune priming, and potentially increase responsiveness to immunotherapies. Here, we presented the efficacy and safety of H101 combined with immune checkpoint inhibitors (ICIs) in patients with liver metastatic gastric cancer. Methods: In this multi-center, phase II trial (the TROJAN 021 study, ChiCTR1900027922), patients with liver metastatic gastric cancer received 2 cycles of H101 ultrasound guided injections into liver lesions, bi-weekly in combination with anti-PD-1 antibodies and chemotherapy bi-weekly until progression or intolerable toxicity. The primary objective was safety and objective response rate (ORR). Secondary objective included progression-free survival (PFS), overall survival (OS) and disease control rate (DCR). Efficacy assessments were performed every 4 weeks following RECIST v1.1 criteria. PFS and OS were estimated using the Kaplan-Meier method. Results: From September 2020 to September 2022, 21 patients were enrolled. Of them, 18 were males, median age was 66 years (range: 36-71) and ECOG performance status was either 0 (n=15) or 1 (n=6). 10 patients (47.6%) received as first-line therapy, 1 (4.8%) as second-line and 5 (23.8%) as third line and above therapy. The primary endpoint was met with a median PFS of 4.8 months. The median OS was 13.2 months. Objective tumor responses were CR (n=0), PR (n=7), SD (n=12) and PD (n=2). ORR was 33.3% (7/21), and DCR was 90.5% (19/21). Treatment related adverse events (TRAE) occurred in 12 patients (57.1%). The most frequently observed TRAEs were injection site pain (48.1%), fever (57.1%) and fatigue (23.8%). Three patients (14.3%) had grade 3 treatment-related adverse events. There were no grade 4 and 5 treatment-related adverse events. Grades 3 toxicities included neutropenia (2/21, 9.5%) and hypertension (1/21, 4.8%). Conclusions: These promising results show that combination of Recombinant Human Adenovirus Type 5 (H101) and ICIs demonstrated acceptable toxicity and promising antitumor efficacy in patients with liver metastatic gastric cancer. Further validation of the efficacy in a randomized prospective trial is warranted. Clinical trial information: ChiCTR1900027922.

BackgroundMedication adherence and the management of adverse drug reactions (ADRs) are crucial to the efficacy of antitumor drugs. A WeChat applet, also known as a “Mini Program,” is similar to the app but has marked advantages. The development and use of a WeChat applet makes follow-up convenient for patients with cancer. ObjectiveThis study aimed to assess the usability and utility of a newly developed WeChat applet, “DolphinCare,” among patients with cancer in Shanghai. MethodsA qualitative methodology was used to obtain an in-depth understanding of the experiences of patients with cancer when using DolphinCare from the usability and utility aspects. The development phase consisted of 2 parts: alpha and beta testing. Alpha testing combined the theory of the Fogg Behavior Model and the usability model. Alpha testing also involved testing the design of DolphinCare using a conceptual framework, which included factors that could affect medication adherence and ADRs. Beta testing was conducted using in-depth interviews. In-depth interviews allowed us to assist the patients in using DolphinCare and understand whether they liked or disliked DolphinCare and found it useful. ResultsWe included participants who had an eHealth Literacy Scale (eHEALS) score of ≥50%, and a total of 20 participants were interviewed consecutively. The key positive motivators described by interviewers were to be reminded to take their medications and to alleviate their ADRs. The majority of the patients were able to activate and use DolphinCare by themselves. Most patients indicated that their trigger to follow-up DolphinCare was the recommendation of their known and trusted health care professionals. All participants found that labels containing the generic names of their medication and the medication reminders were useful, including timed pop-up push notifications and text alerts. The applet presented the corresponding information collection forms of ADRs to the patient to fill out. The web-based consultation system enables patients to consult pharmacists or physicians in time when they have doubts about medications or have ADRs. The applet had usabilities and utilities that could improve medication adherence and the management of ADRs among patients with cancer. ConclusionsThis study provides preliminary evidence regarding the usability and utility of this type of WeChat applet among patients with cancer, which is expected to be promoted for managing follow-up among other patients with other chronic disease.

Lymphotoxin α (LTα) is a soluble factor produced by activated lymphocytes which is cytotoxic to tumor cells. Although a promising candidate in cancer therapy, the application of recombinant LTα has been limited by its instability and toxicity by systemic administration. Secreted LTα interacts with several distinct receptors for its biological activities. Here, we report a TNFR1-selective human LTα mutant (LTα Q107E) with potent antitumor activity. Recombinant LTα Q107E with N-terminal 23 and 27 aa deletion (named LTα Q1 and Q2, respectively) showed selectivity to TNFR1 in both binding and NF-κB pathway activation assays. To test the therapeutic potential, we constructed an oncolytic adenovirus (oAd) harboring LTα Q107E Q2 mutant (named oAdQ2) and assessed the antitumor effect in mouse xenograft models. Intratumoral delivery of oAdQ2 inhibited tumor growth. In addition, oAdQ2 treatment enhanced T cell and IFNγ-positive CD8 T lymphocyte infiltration in a human PBMC reconstituted-SCID mouse xenograft model. This study provides evidence that reengineering of bioactive cytokines with tissue or cell specific properties may potentiate their therapeutic potential of cytokines with multiple receptors.