Prevent Tumor Cell Research Articles

Targeting the Molecules in EMT: A Potential Therapeutic Opportunity in Breast Cancer.

Breast Cancer (BC) is one of the most frequently occurring diseases in women, accounting for 90% of cancer-related deaths in women. Tumor cells can invade nearby tissues and spread to distant organs by metastasis. The epithelialmesenchymal transition or EMT, which involves a number of transcription factors and signaling pathways, is a mechanism by which cells of the epithelium change into mesenchymal type capable of motility, invasion, and metastasis. EMT has grown to be a more intriguing target for developing cutting-edge treatment approaches since it is involved in diverse malignant transformation-related activities. Besides preventing tumor cell invasion and spread and the development of metastatic lesions, anti-EMT treatment methods also lessen cancer stemness and improve the efficacy of more traditional chemotherapeutics. EMT is, therefore, a desirable target in oncology. This review gives an overview of EMT, various markers of EMT, and different inhibitors used in therapies targeting EMT in BC.

β-hydroxybutyrate resensitizes colorectal cancer cells to oxaliplatin by suppressing H3K79 methylation in vitro and in vivo

BackgroundKetone β-hydroxybutyrate (BHB) has been reported to prevent tumor cell proliferation and improve drug resistance. However, the effectiveness of BHB in oxaliplatin (Oxa)-resistant colorectal cancer (CRC) and the underlying mechanism still require further proof.MethodsCRC-Oxa-resistant strains were established by increasing concentrations of CRC cells to Oxa. CRC-Oxa cell proliferation, apoptosis, invasion, migration, and epithelial-mesenchymal transition (EMT) were checked following BHB intervention in vitro. The subcutaneous and metastasis models were established to assess the effects of BHB on the growth and metastasis of CRC-Oxa in vivo. Eight Oxa responders and seven nonresponders with CRC were enrolled in the study. Then, the serum BHB level and H3K79me, H3K27ac, H3K14ac, and H3K9me levels in tissues were detected. DOT1L (H3K79me methyltransferase) gene knockdown or GNE-049 (H3K27ac inhibitor) use was applied to analyze further whether BHB reversed CRC-Oxa resistance via H3K79 demethylation and/or H3K27 deacetylation in vivo and in vitro.ResultsFollowing BHB intervention based on Oxa, the proliferation, migration, invasion, and EMT of CRC-Oxa cells and the growth and metastasis of transplanted tumors in mice were suppressed. Clinical analysis revealed that the differential change in BHB level was associated with drug resistance and was decreased in drug-resistant patient serum. The H3K79me, H3K27ac, and H3K14ac expressions in CRC were negatively correlated with BHB. Furthermore, results indicated that H3K79me inhibition may lead to BHB target deletion, resulting in its inability to function.Conclusionsβ-hydroxybutyrate resensitized CRC cells to Oxa by suppressing H3K79 methylation in vitro and in vivo.

Efficacy of GCN2 inhibition by a novel small molecule AP030 in acute leukemia.

6532 Background: GCN2 is an evolutionarily conserved kinase and a pivotal regulator of the Integrated Stress Response (ISR) that is activated in response to amino acid scarcity. Active GCN2 phosphorylates translation initiation factor eIF2α resulting in the attenuation of global protein synthesis. ISR signaling primarily promotes cell survival but may trigger cell death, dependent on the cellular context. In hematological tumors GCN2 promotes tumor cell survival under conditions of nutrient scarcity. Several GCN2 inhibitors are in clinical development for treatment of both solid and hematological tumors. Here, we describe the preclinical results of a novel, selective ATP-competitive inhibitor of GCN2. Methods: GCN2 inhibition by AP030 was determined using a biochemical Lanthascreen assay and a cell based HTRF assay measuring eIF2a phosphorylation following stimulation with Borrelidin. Kinase selectivity was determined using KinomeScan, and bespoke biochemical and cell-based assays. Interaction of AP030 with GCN2 was determined using X-ray crystallography. AP030 activity in disease-relevant tumor cell lines was determined using cell viability, caspase activation, protein expression and qPCR gene expression endpoints. Inhibition of hematological tumor growth and induction of cell death was investigated in patient samples, and ALL and AML in vivo animal models. Results: Potent inhibition of GCN2 in the Lanthascreen assay was demonstrated with AP030 (Ki of 4.4nM). Following stimulation with Borrelidin, AP030 inhibited eIF2a phosphorylation with an IC50 of 50.8nM and inhibited downstream targets CHAC1 and DDIT3 measured by qPCR. X-ray crystallography confirmed that AP030 binds to the ATP-binding site of GCN2. The KinomeScan confirmed that AP030 was highly selective against the human kinome. AP030 led to partial or complete reduction of AML cell line viability as a single agent and acted synergistically with asparaginase in ALL cell lines. Caspase 3/7 induction was observed in the AML and ALL cell lines evaluated and AP030 increased the proportion of cells undergoing apoptosis in AML patient primary samples. In the CCRF-CEM ALL systemic in vivo tumor model AP030 inhibited tumor growth in combination with asparaginase (TGI 79.33%). Treatment with 0.5-5mg/kg (q.d.) of AP030 resulted in dose-dependent tumor growth inhibition and regression of the MOLM-16 AML in vivo model (TGI 97.37% 5mg/kg). RNA sequencing of residual tumor cells revealed disruption of amino acid and protein metabolism, consistent with GCN2 inhibition. Conclusions: Targeting hematological tumor reliance on the GCN2 arm of the ISR during nutrient scarcity is a novel approach to preventing tumor cell survival. AP030 a novel, potent, selective, ATP-competitive kinase inhibitor has been shown to lead to impressive efficacy in acute leukemia. Based on these preclinical results, a phase 1/2 study has been initiated in AML.

The role of PD-1/PD-L1 signaling pathway in cancer pathogenesis and treatment: a systematic review

Aim: Cancer as a complex disease poses significant challenges for both diagnosis and treatment. Researchers have been exploring various avenues to find effective therapeutic strategies, with a particular emphasis on cellular signaling pathways and immunotherapy. One such pathway that has recently been suggested is the PD-1/PD-L1 pathway, which is an immune checkpoint signaling system that plays an important role in regulating the immune system and maintaining tissue homeostasis. Cancer cells exploit this pathway by producing PD-L1, which attaches to PD-1 on T cells, thus inhibiting immune responses and enabling the cancer cells to escape detection by the immune system. This study aimed to evaluate the role of the PD-1/PD-L1 pathway in cancer pathogenesis and treatment. Method: This study was performed based on the principles of Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). All in vitro , in vivo , and clinical studies that were published in English have been considered during a thorough search of the Scopus, Web of Science, and PubMed databases without date restriction until March 2024. Results: According to the studies reviewed, the PD-1/PD-L1 signaling axis suggests promising therapeutic effects on various types of cancers such as non-small cell lung cancer, melanoma, breast cancer, hepatocellular carcinoma, squamous cell carcinoma, and colorectal cancer, among others. Additionally, research suggests that immune checkpoint inhibitors that block PD1/PD-L1, such as pembrolizumab, atezolizumab, nivolumab, durvalumab, cemiplimab, avelumab, etc. , can effectively prevent tumor cells from escaping the immune system. Moreover, there might be a possible interaction between microbiome, obesity, etc. on immune mechanisms and on the immune checkpoint inhibitors (ICIs). Conclusion: Although we have gained considerable knowledge about ICIs, we are still facing challenges in effectively prescribing the appropriate ICIs for individual patients. This is largely due to the complex interactions between different intracellular pathways, which need to be thoroughly studied. To resolve this issue, it is necessary to conduct more reliable clinical trials that can produce a scientific consensus.

Impairing hydrolase transport machinery prevents human melanoma metastasis

Metastases are the major cause of cancer-related death, yet, molecular weaknesses that could be exploited to prevent tumor cells spreading are poorly known. Here, we found that perturbing hydrolase transport to lysosomes by blocking either the expression of IGF2R, the main receptor responsible for their trafficking, or GNPT, a transferase involved in the addition of the specific tag recognized by IGF2R, reduces melanoma invasiveness potential. Mechanistically, we demonstrate that the perturbation of this traffic, leads to a compensatory lysosome neo-biogenesis devoided of degradative enzymes. This regulatory loop relies on the stimulation of TFEB transcription factor expression. Interestingly, the inhibition of this transcription factor playing a key role of lysosome production, restores melanomas’ invasive potential in the absence of hydrolase transport. These data implicate that targeting hydrolase transport in melanoma could serve to develop new therapies aiming to prevent metastasis by triggering a physiological response stimulating TFEB expression in melanoma.

FAM53B promotes pancreatic ductal adenocarcinoma metastasis by regulating macrophage M2 polarization.

Our study investigated the role of FAM53B in regulating macrophage M2 polarization and its potential mechanisms in promoting pancreatic ductal adenocarcinoma (PDAC) metastasis. To further investigate the role of FAM53B in regulating macrophage M2 polarization and its potential mechanism in promoting PDAC metastasis. Our goal is to determine how FAM53B affects macrophage M2 polarization and to define its underlying mechanism in PDAC metastasis. Cell culture and various experiments, including protein analysis, immunohistochemistry, and animal model experiments, were conducted. We compared FAM53B expression between PDAC tissues and healthy tissues and assessed the correlation of FAM53B expression with clinical features. Our study analyzed the role of FAM53B in macrophage M2 polarization in vitro by examining the expression of relevant markers. Finally, we used a murine model to study the role of FAM53B in PDAC metastasis and analyzed the potential underlying mechanisms. Our research showed that there was a significant increase in FAM53B levels in PDAC tissues, which was linked to adverse tumor features. Experimental findings indicated that FAM53B can enhance macrophage M2 polarization, leading to increased anti-inflammatory factor release. The results from the mouse model further supported the role of FAM53B in PDAC metastasis, as blocking FAM53B prevented tumor cell invasion and metastasis. FAM53B promotes PDAC metastasis by regulating macrophage M2 polarization. This discovery could lead to the development of new strategies for treating PDAC. For example, interfering with the FAM53B signaling pathway may prevent cancer spread. Our research findings also provide important information for expanding our understanding of PDAC pathogenesis.

Exploring dendritic cell subtypes in cancer immunotherapy: unraveling the role of mature regulatory dendritic cells.

Dendritic cells (DCs) possess a specialized function in presenting antigens and play pivotal roles in both innate and adaptive immune responses. Their ability to cross-present antigens from tumor cells to naïve T cells is instrumental in generating specific T-cell-mediated antitumor responses, crucial for controlling tumor growth and preventing tumor cell dissemination. However, within a tumor immune microenvironment (TIME), the functions of DCs can be significantly compromised. This review focuses on the profile, function, and activation of DCs, leveraging recent studies that reveal insights into their phenotype acquisition, transcriptional state, and functional programs through single-cell RNA sequence (scRNA-seq) analysis. Additionally, the therapeutic potential of DC-mediated tumor antigen sensing in priming antitumor immunity is discussed.

Design, Synthesis, and Biological Evaluation of Novel Quinazoline Derivatives Possessing a Trifluoromethyl Moiety as Potential Antitumor Agents.

A novel series of trifluoromethyl-containing quinazoline derivatives with a variety of functional groups was designed, synthesized, and tested for their antitumor activity by following a pharmacophore hybridization strategy. Most of the 20 compounds displayed moderate to excellent antiproliferative activity against five different cell lines (PC3, LNCaP, K562, HeLa, and A549). After three rounds of screening and structural optimization, compound 10 b was identified as the most potent one, with IC50 values of 3.02, 3.45, and 3.98 μM against PC3, LNCaP, and K562 cells, respectively, which were comparable to the effect of the positive control gefitinib. To further explore the mechanism of action of 10 b against cancer, experiments focusing on apoptosis induction, cell cycle arrest, and cell migration assay were conducted. The results showed that 10 b was able to induce apoptosis and prevent tumor cell migration, but had no effect on the cell cycle of tumor cells.

Loss of GABARAP mediates resistance to immunogenic chemotherapy in multiple myeloma

AbstractImmunogenic cell death (ICD) is a form of cell death by which cancer treatments can induce a clinically relevant antitumor immune response in a broad range of cancers. In multiple myeloma (MM), the proteasome inhibitor bortezomib is an ICD inducer and creates durable therapeutic responses in patients. However, eventual relapse and resistance to bortezomib appear inevitable. Here, by integrating patient transcriptomic data with an analysis of calreticulin (CRT) protein interactors, we found that GABA type A receptor–associated protein (GABARAP) is a key player whose loss prevented tumor cell death from being perceived as immunogenic after bortezomib treatment. GABARAP is located on chromosome 17p, which is commonly deleted in patients with high risk MM. GABARAP deletion impaired the exposure of the eat-me signal CRT on the surface of dying MM cells in vitro and in vivo, thus reducing tumor cell phagocytosis by dendritic cells and the subsequent antitumor T-cell response. Low GABARAP was independently associated with shorter survival in patients with MM and reduced tumor immune infiltration. Mechanistically, we found that GABARAP deletion blocked ICD signaling by decreasing autophagy and altering Golgi apparatus morphology, with consequent defects in the downstream vesicular transport of CRT. Conversely, upregulating autophagy using rapamycin restored Golgi morphology, CRT exposure, and ICD signaling in GABARAPKO cells undergoing bortezomib treatment. Therefore, coupling an ICD inducer, such as bortezomib, with an autophagy inducer, such as rapamycin, may improve patient outcomes in MM, in which low GABARAP in the form of del(17p) is common and leads to worse outcomes.

Urolithin A affects cellular migration and modulates matrix metalloproteinase expression in colorectal cancer cells.

Colorectal cancer (CRC) is the world's second most common gastrointestinal malignancy. Preventing tumor cell proliferation and dissemination is critical for patient survival. Polyphenols have a variety of health advantages and can help prevent cancer. The current study examined different cellular activities of the gut-microbiota metabolite urolithin A (UA) on several colon cancer cell lines. The results revealed that UA suppressed cell growth in a dose- and time-dependent manner. In the current investigation, UA substantially affected cell migration in the wound-healing experiment and greatly decreased the number of colonies generated in each CRC cell culture. UA decreased cellular migration in CRC cells 48 h after treatment, which was significant (p < .001) compared to the migration rate in untreated cells. When compared to untreated cells, UA slowed the process of colony formation by reducing the number of colonies or altering their morphological shape. The western blot analysis investigation revealed that UA inhibits cellular metastasis by lowering the expression levels of matrix metalloproteinases 1 and 2 (MMP1 and MMP2) by more than 43% and 41% (p < .001) in HT29, 28% and 149% (p < .001) in SW480, and 90% and 74% (p < .001) in SW620, respectively, at a 100 µM dosage of UA compared to the control. Surprisingly, at a 100 µM dosage of UA, the expression levels of the tissue inhibitor of metalloproteinases 1 (TIMP1) were elevated in HT29, SW480, and SW620 cells treated with 100 µM of UA by more than 89%, 57%, and 29%, respectively. Our findings imply that UA has anticancer properties and might be used therapeutically to treat CRC. The findings provided the first indication of the influence of UA on cellular migration and metastasis in colon cancer cells. All of these data showed that UA might be used as an adjuvant therapy in the treatment of various forms of CRC.

KIAA0040 enhances glioma growth by controlling the JAK2/STAT3 signalling pathway.

The role of KIAA0040 role in glioma development is not yet understood despite its connection to nervous system diseases. In this study, KIAA0040 expression levels were evaluated using qRT-PCR, WB and IHC, and functional assays were conducted to assess its impact on glioma progression, along with animal experiments. Moreover, WB was used to examine the impact of KIAA0040 on the JAK2/STAT3 signalling pathway. Our study found that KIAA0040 was increased in glioma and linked to tumour grade and poor clinical outcomes, serving as an independent prognostic factor. Functional assays showed that KIAA0040 enhances glioma growth, migration and invasion by activating the JAK2/STAT3 pathway. Of course, KIAA0040 enhances glioma growth by preventing tumour cell death and promoting cell cycle advancement. Our findings suggest that targeting KIAA0040 could be an effective treatment for glioma due to its role in promoting aggressive tumour behaviour and poor prognosis.

Abstract 5240: Novel CD3-Fusion Receptor enables combination of T-cell engagers and allogeneic CAR T cells to promote enhanced antitumor activity and overcome antigen escape

Abstract Chimeric antigen receptor (CAR) T cells have shown remarkable clinical success in the treatment of hematologic malignancies. However, the durability of response of CAR T therapy can be impaired by heterogenous expression of the CAR-specific target antigen (1° Ag) on tumors. In combination with a CAR, T-cell engagers (TCEs) that target additional tumor antigen (2° Ag) can be a unique approach to address tumor heterogeneity and overcome antigen escape. Engineered induced pluripotent stem cell (iPSC) master cell lines are a renewable source material from which iPSC-derived CAR T (CAR-iT) cells can be manufactured and administered in an off-the-shelf manner. In developing allogeneic CAR-iT cells, the T-cell receptor (TCR) must be eliminated to prevent graft-versus-host disease. However, the absence of TCR expression leads to loss of surface CD3 and a corresponding loss of TCE compatibility. Here we discuss a novel CD3ε fusion receptor (CD3-FR) with a modified transmembrane and endodomain, which allows for CD3 surface expression on TCR-less T cells and effective combination of off-the-shelf allogeneic CAR-T cells and TCEs. CAR+ CD3-FR+ iPSCs were differentiated into CAR-iT cells, uniformly expressing both modalities (&amp;gt;95% CAR+, &amp;gt;90% CD3ε+) and absent of TCR. To demonstrate that CD3-FR+ CAR-iT cells can elicit TCE-dependent activity, 1° Ag- (CD19-)/2° Ag+ (EpCAM+) target cells were used in cytotoxicity assays. As shown, CD3-FR- CAR-iT cells failed to kill 1° Ag- target cells. In contrast, CD3-FR+ CAR-iT cells demonstrated potent activity toward the target cells (&amp;gt;80% cytolysis) but only in the presence of the TCE targeting 2° Ag. To test the ability of CD3-FR+ CAR-iT cells to mitigate antigen escape, we used a tumor cell population heterogenous for the CAR-specific target (50% 1° Ag-) but homogenous for TCE-specific target (100% 2° Ag+). In co-culture assays, CD3-FR- CAR-iT cells failed to prevent tumor cell growth due to 1° Ag- tumor escape. However, CD3-FR+ CAR-iT cells in the presence of TCE exhibited robust control (80% cytolysis) of the heterogenous tumor, mitigating 1° Ag- tumor escape via targeting of 2° Ag. Next, we tested the ability of CD3-FR+ CAR-iT cells to control heterogeneous tumor in vivo in a disseminated leukemia model. As expected, CD3-FR+ CAR-iT cells exhibited significantly better tumor growth inhibition in the presence of TCE (p-value &amp;lt;0.005) compared to controls lacking the CD3-FR modality. Ex vivo analysis of tumor in the bone marrow confirmed 1° Ag- tumor escape in the control treated mice, but not in mice treated with CD3-FR+ CAR-iT and TCE targeting 2° Ag. Taken together, these studies present a novel opportunity to leverage a novel CD3 fusion receptor and enable combination of TCEs with engineered off-the-shelf CAR T-cell products, uniquely harnessing two potent therapeutic modalities for improving cancer therapy. Citation Format: Dan Lu, Eigen Peralta, Hui-Yi Chu, Soo Park, Masanao Tsuda, Earl Avramis, Matthew Denholtz, Alec Witty, Tom Lee, Bahram Valamehr. Novel CD3-Fusion Receptor enables combination of T-cell engagers and allogeneic CAR T cells to promote enhanced antitumor activity and overcome antigen escape [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5240.

Pharmacological Targeting of Ferroptosis in Cancer Treatment

A non-apoptotic iron-dependent form of Regulated Cell Death (RCD) known as ferroptosis is brought on by an excess of harmful lipid peroxides and iron overload. Inhibiting the antioxidant defense system results in overwhelming of GSH dependent pathway and building up iron-dependent Reactive Oxygen Species (ROS) that react with polyunsaturated fatty acids in large quantities can both cause ferroptosis. Recent research has shown that ferroptosis holds a great deal of promise for preventing tumor cell resistance and limiting growth and spread. Emerging evidence also suggests that ferroptosis plays a dual role in human cancer. However, the precise underlying molecular mechanisms and their different role in tumorigenesis are unclear. Therefore, in this review we summarize and briefly present the key pathways of ferroptosis, its dual role as an oncogenic and as a tumor suppressor event in human cancers, paying special attention to the regulation of ferroptosis along with a variety of current medications and naturally occurring substances that may one day be used to target ferroptosis in tumor cells. Thus, addressing this sort of cell death could be seen as a potentially expanding technique in cancer treatment. Consequently, this will offer crucial viewpoints for next research on ferroptosis-based cancer treatment.&#x0D; Keywords: Ferroptosis, antioxidant defense system, Cancer

Immunotherapy in hepatocellular carcinoma: an overview of immune checkpoint inhibitors, drug resistance, and adverse effects

Abstract Hepatocellular carcinoma (HCC) is a concerning liver cancer with rising incidence and mortality rates worldwide. The effectiveness of traditional therapies in managing advanced HCC is limited, necessitating the development of new therapeutic strategies. Immune checkpoint inhibitors (ICIs) have emerged as a promising strategy for HCC management. By preventing tumor cells from evading immune surveillance through immunological checkpoints, ICIs can restore the immune system’s ability to target and eliminate tumors. While ICIs show promise in enhancing the immune response against malignancies, challenges such as drug resistance and adverse reactions hinder their efficacy. To address these challenges, developing individualized ICI treatment strategies is critical. Combining targeted therapy and immunotherapy holds the potential for comprehensive therapeutic effects. Additionally, biomarker-based individualized ICI treatment strategies offer promise in predicting treatment response and guiding personalized patient care. Future research should explore emerging ICI treatment methods to optimize HCC immunotherapy. This review provides an overview of ICIs as a new treatment for HCC, demonstrating some success in promoting the tumor immune response. However, drug resistance and adverse reactions remain important considerations that must be addressed. As tailored treatment plans evolve, the prospect of immunotherapy for HCC is expected to grow, offering new opportunities for improved patient outcomes.

Mitochondrial targeting derivatives of honokiol enhanced selective antitumor activity in NCI-H446 cells and decreased in vivo toxicity in Caenorhabditis elegans

Mitochondria, responsible for ATP production and apoptosis regulation, play a key role in cancer cells. Honokiol regulates apoptosis through the endogenous mitochondrial pathway but does not specifically target tumor cells. We designed 28 novel derivatives of honokiol using triple-function delocalized lipophilic cations such as berberine and F16 as mitochondrion-targeting carriers. While all derivatives exhibited enhanced cytotoxicity toward tumor cells compared to honokiol, the derivative 2E-3-F16 exhibited a substantial tumor cell selectivity between NCI-H446 cancer cells and HBE cells by one order of magnitude and enhanced the sensitivity of A549 cells to cisplatin. Mechanistically, it targeted mitochondria and induced apoptosis by preventing tumor cells from entering the G0/G1 phases as well as inducing an abnormal elevation of reactive oxygen species, thereby decreasing the mitochondrial membrane potential level. It also showed lower toxicity toward Caenorhabditis elegans than honokiol. This study provides a possible method for developing mitochondrion-targeting antitumor drugs with high efficiency and low toxicity based on natural products.

PP157 Metformin prevents tumor cell growth and invasion of human hormonal breast cancer cells via the diabetes-related gene inhibition

PP157 Metformin prevents tumor cell growth and invasion of human hormonal breast cancer cells via the diabetes-related gene inhibition

Affinity of Anti-CD19 Antibodies Determines Subsequent CART19 Activation, Apoptosis and CRS in Preclinical Models

Our group has reported that transient CD19 antigen masking of leukemic cells with the CD19 monoclonal antibody (mAb), tafasitamab, resulted in reduction of CD19 chimeric antigen receptor T cell (CART19) apoptosis, enhanced CAR T proliferation, improved anti-tumor activity, diminished tumor pyroptosis, and reduced severity of cytokine release syndrome (CRS) in preclinical models. In this report, we aimed to study the mAb characteristics responsible for these observations. Specifically, we hypothesized that binding affinity of CD19 mAbs might affect the subsequent activation and apoptosis of CART19 as well as tumor cell pyroptosis in preclinical models. To test our hypothesis, we first determined the affinities of the CD19-targeting antibodies tafasitamab, HD37 and FMC63 to recombinant human CD19 protein. Tafasitamab demonstrated the strongest binding affinity among the three tested antibodies [tafasitamab ( K D: 1.0±0.2 nM), HD37 ( K D: 4.1±0.3 nM), FMC63 ( K D: 3.4±1.2 nM)]. Next, we studied CART19 apoptosis in the presence of these CD19 mAbs with different binding affinities. Here, we co-cultured CART19, CD19 + mantle cell lymphoma JeKo, and 400 μg/mL of CD19 mAb for 1 hour and measured CD3 + 7-AAD - Annexin V + T cells with flow cytometry. The number of apoptotic CART19 cells was significantly reduced by tafasitamab co-treatment compared to HD37, FMC63, or control IgG [control IgG (mean = 19.1, standard deviation (SD) = 0.8), tafasitamab (mean = 13.1, SD = 2.9), HD37 (mean = 17.8, SD = 0.8), FMC63 (mean = 18.4, SD = 1.0)]. We also performed an in vitro high mobility group box 1 (HMGB1) assay to assess if different affinities of the CD19 mAbs affect tumor cell pyroptosis triggered by CART19. Here, we co-cultured CART19, CD19 + JeKo, and 400 μg/mL of CD19 mAb for 24 hours and assessed HMGB1 on JeKo. In analogy to the apoptosis data, tafasitamab was the only mAb that prevented tumor cell pyroptosis, indicated by reduced HMGB1 expression (Fig 1A). Given these results, we aimed to study the impact of CD19 occupancy with different CD19 mAbs prior to CART19 infusion on tumor pyroptosis in vivo. We utilized a mouse model that mimics CAR T toxicities. Immunocompromised NSG mice were inoculated via tail vein with 5x10 6 leukemic cells derived from patients with relapsed/refractory acute lymphoblastic leukemia. Two weeks later (day -7), tumor burden was assessed by peripheral blood sampling. Leukemic cells were defined as murine CD45 -, human CD45 + CD19 + CD20 + via flow cytometry, and volumetric absolute number was calculated. Mice were then randomized according to tumor burden to receive IgG control [Group 1 (G1)], tafasitamab (G2), HD37 (G3), or FMC63 (G4) (5 mg/kg, ip) at day -7. CRS was determined by weight loss, development of motor weakness, poor body posture, and elevated serum cytokine levels. At day 0, all mice received 3x10 6 luciferase + CART19 via tail vein. Mice were monitored with daily bioluminescent imaging (BLI) to track and quantify CART19 expansion and physical assessment to detect toxicity. BLI on day 4 revealed that CART19 expansion in the tafasitamab-treated group (G2, mean = 1x10 7, SD = 2.3x10 7) was significantly lower than in the control group (mean = 3.5x10 7, SD = 9.3x10 7), the HD37-treated group (G3, mean = 4x10 7, SD = 6.6x10 7), and the FMC63-treated group (G4, mean = 2x10 7, SD = 3.59x10 7), [G1 vs G2: 95% confidence interval (CI) 3.5x10 7 to 1.1x10 8, p &amp;lt;0.0001, G1 vs G3: 95% CI -7.5x10 7 to -1.1x10 8, p=0.005, G1 vs G4: 95% CI -4.5x10 7 to 1.9x10 7, p=0.71] indicating that tafasitamab pretreatment significantly reduced early activation of CART19 compared to IgG control and HD37 in this model. Mice were bled on day 4 to analyze plasma cytokine. Tafasitamab-treated mice (G2) secreted significantly less IFNγ (Fig 1B), IL10 (Mean G1: 78, G2: 2.52, G3: 12.2, G4: 13.9 pg/mL), MDC (Mean G1: 4072, G2: 445, G3: 921, G4: 1364 pg/mL), and MIP1β (Mean G1: 283, G2: 59.1, G3: 148, G4: 123 pg/mL) compared to G1, G3, and G4. Satellite mice were euthanized on day 1 and spleens were harvested. Western blot analysis of splenocytes revealed that G1, 3, and 4 showed significantly lower expression of apoptosis-inducing protein gasdermin E on leukemic cells compared to G2, indicating reduced tumor pyroptosis in G2. In summary, application of the high affinity mAb tafasitamab prior to CART19 resulted in reduced CAR T apoptosis, diminished tumor cell pyroptosis, and reduction of CRS compared to lower affinity CD19 mAbs in preclinical models.

A Phase 2 Trial of Talazoparib and Avelumab in Genomically Defined Metastatic Kidney Cancer

BackgroundAlthough different kidney cancers represent a heterogeneous group of malignancies, multiple subtypes including Von Hippel-Lindau (VHL)-altered clear cell renal cell carcinoma (ccRCC), fumarate hydratase (FH)- and succinate dehydrogenase (SDH)-deficient renal cell carcinoma (RCC), and renal medullary carcinoma (RMC) are affected by genomic instability. Synthetic lethality with poly ADP-ribose polymerase inhibitors (PARPis) has been suggested in preclinical models of these subtypes, and paired PARPis with immune checkpoint blockade (ICB) may achieve additive and/or synergistic effects in patients with previously treated advanced kidney cancers. ObjectiveTo evaluate combined PARPi + ICB in treatment-refractory metastatic kidney cancer. Design, setting, and participantsWe conducted a single-center, investigator-initiated phase 2 trial in two genomically selected advanced kidney cancer cohorts: (1) VHL-altered RCC with at least one prior ICB agent and one vascular endothelial growth factor (VEGF) inhibitor, and (2) FH- or SDH-deficient RCC with at least one prior ICB agent or VEGF inhibitor and RMC with at least one prior line of chemotherapy. InterventionPatients received talazoparib 1 mg daily plus avelumab 800 mg intravenously every 14 d in 28-d cycles. Outcome measurements and statistical analysisThe primary endpoint was objective response rate (ORR) by Immune Response Evaluation Criteria in Solid Tumors at 4 mo, and the secondary endpoints included progression-free survival (PFS), overall survival, and safety. Results and limitationsCohort 1 consisted of ten patients with VHL-altered ccRCC. All patients had previously received ICB. The ORR was 0/9 patients; one patient was not evaluable due to missed doses. In this cohort, seven patients achieved stable disease (SD) as the best response. The median PFS was 3.5 mo (95% confidence interval [CI] 1.0, 3.9 mo). Cohort 2 consisted of eight patients; four had FH-deficient RCC, one had SDH-deficient RCC, and three had RMC. In this cohort, six patients had previously received ICB. The ORR was 0/8 patients; two patients achieved SD as the best response and the median PFS was 1.2 mo (95% CI 0.4, 2.9 mo). The most common treatment-related adverse events of all grades were fatigue (61%), anemia (28%), nausea (22%), and headache (22%). There were seven grade 3–4 and no grade 5 events. ConclusionsThe first clinical study of combination PARPi and ICB therapy in advanced kidney cancer did not show clinical benefit in multiple genomically defined metastatic RCC cohorts or RMC. Patient summaryWe conducted a study to look at the effect of two medications, talazoparib and avelumab, in patients with metastatic kidney cancer who had disease progression on standard treatment. Talazoparib blocks the normal activity of molecules called poly ADP-ribose polymerase, which then prevents tumor cells from repairing themselves and growing, while avelumab helps the immune system recognize and kill cancer cells. We found that the combination of these agents was safe but not effective in specific types of kidney cancer.

Monocarboxylate transporter blockage-enabled lactate redistribution reshapes immunosuppressive tumor microenvironment and enhances chemodynamic immunotherapy

The immunosuppressive tumor microenvironment (TME) hinders T cells infiltration and prevents a sufficient immune response. Monocarboxylate transporter (MCT)-mediated lactate accumulation not only leads to tumor acidification but also recruits immunosuppressive cells, which greatly limits the therapeutic efficacy of immunotherapy. In this work, we report an MCT blockage strategy using a manganese-based metal organic framework (MnMOF) for enhanced chemodynamic immunotherapy. Syrosingopine (Syr) was found to prevent tumor cells from excreting lactate into the extracellular environment via MCT, thus lowering the intracellular pH and increasing the intracellular H2O2 levels. Afterward, the Mn ion-triggered Fenton-like reaction was amplified by the increased H2O2 levels and strongly acidic conditions in tumor cells. The dying tumor cells induced by chemodynamic therapy released damage-associated molecular patterns, promoting the activation and proliferation of T cells. Furthermore, Syr reduced the lactate levels of the extracellular TME to restore immune activity, including the M1 polarization of tumor-associated macrophages, the activation of dendritic cells and cytotoxic T lymphocytes, and a reduction in immunosuppressive cells. Overall, this Syr@PEG-MnMOF74 nanocomplex enhanced chemodynamic immunotherapy and effectively inhibited the invasion and metastasis of CT26 tumors.

Fam198b as a novel biomarker for gastric cancer and a potential therapeutic target to prevent tumor cell proliferation dysregulation

BackgroundIt has been reported that the human family with sequence similarity 198, member B (Fam198b) play an important role in the occurrence and development of various cancers. Nevertheless, its function in gastric cancer is not completely clear. Hereby, we investigated the function and prognostic value of Fam198b in gastric cancer and further validated the results in gastric cancer through a series of in vitro experiments. MethodsWe used R software and online bioinformatics analysis tools-GEPIA2, TIMER2, Kaplan-Meier plotter, cBioPortal, TISIDB COSMIC, and STRING to study the characteristics and functions of Fam198b in GC, such as aberrant expression, prognostic value, genomic alterations, immune microenvironment, anticancer drug sensitivity, and related signaling pathways. In addition, in vitro experiments such as immunohistochemistry (IHC), cell function experiments, and signaling pathway experiments were performed to validate the key conclusions. ResultFam198b is obviously highly expressed in gastric cancer, and its expression is intensively correlated with tumor prognosis. The etiology of abnormal Fam198b expression was superficially investigated and validated by associating genomic alterations and the immune microenvironment. Furthermore, Fam198b is intensively correlated with the sensitivity of multiple antitumor drugs. It was demonstrated by functional enrichment analysis that Fam198b was linked to myogenesis, angiogenesis, epithelial mesenchymal transition and cytokine binding. It was observed in vitro experiments that knockdown Fam198b could significantly inhibit tumor cell proliferation and migration. These results were reversed when Fam198b was overexpressed. It was validated by signaling pathway experiments that Fam198b promoted gastric cancer progression by up-regulating the PI3K/AKT/BCL-2 signaling pathway. ConclusionAs a novel biomarker to predict GC prognosis and tumor progression, Fam198b is a promising therapeutic target to reverse tumor progression.