Tumor Cell Survival Research Articles

Fully human monoclonal antibody targeting the cysteine-rich substrate-interacting region of ADAM17 on cancer cells

ADAM17 sheds EGFR/erbB ligands and triggers oncogenic pathways that lead to the progression of solid tumors. We targeted the ADAM17 disintegrin and cysteine rich domain region (D+C) to generate a panel of single-chain antibody fragments (scFvs) that selectively bind to the D or C domains of ADAM17, but not of ADAM10 or ADAM19. From the panel, we selected one scFv, referred to as C12, based on its high binding affinity towards the target, and re-formatted it to a full IgG for further studies. High-resolution cryo-electron microscopy studies documented that the mAb binds to the ADAM17 C-domain that in ADAM proteases, notably ADAM10 and ADAM17, is known to impart substrate-specificity. The C12 mAb significantly inhibited EGFR phosphorylation in cancer cell lines by hindering the cleavage of EGFR ligands tethered to the cell surface. This inhibition provides a mechanism for potential anti-tumor effects, and indeed C12 diminished the viability of a variety of EGFR-expressing cancer cell lines. Cell-based ELISA studies revealed that C12 preferentially bound to activated ADAM17 present on tumor cells, as compared to the autoinhibited ADAM17 that is the predominant form on HEK293 and other non-tumor cells. C12 also exhibited tumor growth inhibition in an ovarian cancer xenograft mouse model. Consistent with its selective tumor cell binding in vitro, radioimmuno PET (positron emission tomography) imaging with 89Zr-DFO-C12 in mouse xenograft models confirmed tumoral accumulation of the C12 mAb.

New Pd(II)-pincer type complexes as potential antitumor drugs: synthesis, nucleophilic substitution reactions, DNA/HSA interaction, molecular docking study and cytotoxic activity.

Two new complexes of Pd(II), [Pd(L1)Cl]Cl (Pd1) and [Pd(L2)Cl]Cl (Pd2), (where L1 = N2,N6-bis(5-methylthiazol-2-yl)pyridine-2,6-dicarboxamide and L2 = N2,N6-di(benzo[d]thiazol-2-yl)pyridine-2.6-dicarboxamide) were synthesized. Characterization of the complexes was performed using elemental analysis, IR, 1H NMR spectroscopy and MALDI-TOF mass spectrometry. The nucleophilic substitution reactions of complexes with L-Methionine (L-Met), L-Cysteine (L-Cys) and guanosine-5'-monophosphate (5'-GMP) were studied by stopped-flow method at physiological conditions (pH = 7.2 and 37 °C). Complex Pd1 was more reactive than Pd2 in all studied reactions, while the order of reactivity of the selected ligands was: L-Met > L-Cys > 5'-GMP. The interaction of complexes with calf thymus-DNA (CT-DNA) was studied by Uv-Vis absorption and fluorescence emission spectroscopy. Competitive binding studies with intercalative agent ethidium bromide (EB) and minor groove binder Hoechst 33258 were performed as well. Both complexes interacted with DNA through intercalation and minor groove binding, where the latter was preferred. Additionally, the interaction of Pd1 and Pd2 complexes with human serum albumin (HSA) was studied employing fluorescence quenching spectroscopy. The results indicate a moderate binding affinity of complexes, with slightly stronger binding of the Pd1. Fluorescence competition experiments with site-markers (eosin Y and ibuprofen) for HSA were used to locate the binding site of Pd1 to the HSA. Additionally, the interaction with DNA and HSA was studied by molecular docking and the revealed results were in good agreement with the experimentally obtained ones. Pd1 complex exhibited cytotoxicity toward human (HCT116) and mouse cell lines (CT26) of colorectal cancer, mouse (4T1) and human (MDA-MB468) breast cancer lines and non-cancerous mouse mesenchymal stem cells (mMSC). In addition, Pd1 complex demonstrated significant selectivity towards cancer cells over non-cancerous mMSC, indicating a high potential to eliminate malignant cells without affecting normal cells. It induced apoptosis in CT26 cells, effectively arrested the cell cycle in the S phase, and selectively down-regulated cyclin D and cyclin E. Moreover, it can alter the expression of cell cycle regulators by increasing p21 and decreasing p-AKT. These findings confirm its ability to disrupt key tumor cell survival signals and suggest that the Pd1 complex is a potent candidate for effective cancer treatment.

DMF-Bimol: Counting mRNA and Protein Molecules in Single Cells with Digital Microfluidics.

Analyzing single-cell protein and mRNA levels yields invaluable insights into cellular functions and the intricacies of biologically heterogeneous systems. Current joint mRNAs and protein analysis methodologies suffer from relative quantification, low sensitivity, possible background interference, and tedious manual manipulation. Therefore, we propose DMF-Bimol that leverages addressable digital microfluidics to automate digital counting of single-cell mRNA and protein based on proximity ligation assay (PLA) and one-step RT-droplet digital PCR (RT-ddPCR). Through an engineered hydrophilic-hydrophobic interface, DMF-Bimol enables efficient single-cell isolation and lossless protein and nucleic acid processing. The closed droplet reaction system enhances the protein concentration and isolates exogenous contaminants, thereby dramatically improving the efficiency of the PLA reaction. The limit of detection of this approach achieves 3313 protein copies, marking a significant 17-fold enhancement in sensitivity over traditional benchtop PLA. This heightened sensitivity also uncovers a lower correlation between mRNA and protein levels in individual cells (Spearman r = 0.255) than bulk results, reflecting the complex relationship in heterogeneous cells. Using DMF-Bimol, we observed a significant upsurge of CD147 protein in CD138+ myeloma cells but consistent levels of CD147 mRNAs compared with normal leukocytes. This discovery indicates a possible consequence of CD147 oncogenic activation that tends to harness protein translation to bolster tumor cell survival and enhance invasiveness, highlighting the potential of DMF-Bimol in unveiling intricate dynamics in translation processes at the single-cell level.

Autophagy is required for mammary tumor recurrence by promoting dormant tumor cell survival following therapy

BackgroundMortality from breast cancer is principally due to tumor recurrence. Recurrent breast cancers arise from the pool of residual tumor cells, termed minimal residual disease, that survive treatment and may exist in a dormant state for 20 years or more following treatment of the primary tumor. As recurrent breast cancer is typically incurable, understanding the mechanisms underlying dormant tumor cell survival is a critical priority in breast cancer research. The importance of this goal is further underscored by emerging evidence suggesting that targeting dormant residual tumor cells in early-stage breast cancer patients may be a means to prevent tumor recurrence and its associated mortality. In this regard, the role of autophagy in dormant tumor cell survival and recurrence remains unresolved, with conflicting reports of both pro-survival/recurrence-promoting and pro-death/recurrence-suppressing effects of autophagy inhibition in dormant tumor cells. Resolving this question has important clinical implications.MethodsWe used genetically engineered mouse models that faithfully recapitulate key features of human breast cancer progression, including minimal residual disease, tumor dormancy, and recurrence. We used genetic and pharmacological approaches to inhibit autophagy, including treatment with chloroquine, genetic knockdown of ATG5 or ATG7, or deletion of BECN and determined their effects on dormant tumor cell survival and recurrence.ResultsWe demonstrate that the survival and recurrence of dormant mammary tumor cells following therapy is dependent upon autophagy. We find that autophagy is induced in vivo following HER2 downregulation and remains activated in dormant residual tumor cells. Using genetic and pharmacological approaches we show that inhibiting autophagy by chloroquine administration, ATG5 or ATG7 knockdown, or deletion of a single allele of the tumor suppressor Beclin 1 is sufficient to inhibit mammary tumor recurrence, and that autophagy inhibition results in the death of dormant mammary tumor cells in vivo.ConclusionsOur findings demonstrate a pro-tumorigenic role for autophagy in tumor dormancy and recurrence following therapy, reveal that dormant tumor cells are uniquely reliant upon autophagy for their survival, and indicate that targeting dormant residual tumor cells by inhibiting autophagy impairs tumor recurrence. These studies identify a pharmacological target for a cellular state that is resistant to commonly used anti-neoplastic agents and suggest autophagy inhibition as an approach to reduce dormant minimal residual disease in order to prevent lethal tumor recurrence.

Evolutionary Sequences and Structural Information-driven Reconstruction of New Insulin-like Growth Factor-I Peptide Variants.

Insulin-like growth factor-I (IGF-I) is crucial in controlling cell growth, proliferation, and apoptosis. Its strong link to the development of cancers such as breast, prostate, lung, thyroid, and colorectal has positioned the IGF-1 signalling pathway as a promising target for novel cancer therapies. When activated, the IGF-1 receptor (IGF-1R) binds to IGF-I, playing a central role in promoting tumour cell growth and survival. In this study, we combined evolutionary sequences with structural and functional data of IGF-1 to reconstruct ancestral sequences and design novel IGF-1 peptide variants. The insulin-like growth factor system exhibits a vast sequence diversity, yet it shares a similar structural topology with conserved three pairs of disulfide linkages. Our study reveals that IGF-1 is associated with the IGF system of cell surface receptors through protein-protein interactions. Reconstructed IGF-1 variants show similar structure fold to reported viral IGF-1 competitive antagonists. This new insight guides the design of novel natural IGF-1 mimic peptides. It enhances our understanding of IGF-1's functionality and opens new avenues for the development of therapeutic peptides and small molecules as anticancer agents.

A Caspase 3‐Hijacking Nanosystem Enhances Cancer Radiotherapy by Suppressing Tumor Repopulation

AbstractRadiotherapy is used in the treatment of ≈50% of patients with cancer. However, tumor repopulation is a major cause of treatment failure after radiotherapy. It is observed that apoptotic tumor following ionizing radiation (IR) accelerated the growth of surviving tumor cells. Here a Gasdermin E and Tannic acid‐based nanoassembly (GT) loaded with manganese tetroxide (Mn3O4) (termed as Mn3O4@GT) is developed to suppress tumor repopulation and improve the treatment outcome of radiotherapy. Mn3O4@GT enables an increase in the reactive oxygen species accumulation in tumor cells, enhancing radiotherapy‐mediated tumor killing. What's more, it can hijack activated caspase 3 to induce tumor pyroptosis, reversing apoptosis‐mediated tumor repopulation. In vivo results shows that Mn3O4@GT significantly reduced the IR induced tumor repopulation by 2.7 fold, resulting in 92% complete regression of tumors. In addition, Mn3O4@GT can sensitize tumors to anti‐PD‐L1 therapy by inducing immunogenic pyroptosis with 85% regression of distant tumors. The caspase 3‐hijacking nanosystem holds a great potential for improving the clinical benefits of radiotherapy.

Structure-based discovery of first inhibitors targeting the helicase activity of human PIF1.

PIF1 is a conserved helicase and G4 DNA binding and unwinding enzyme, with roles in genome stability. Human PIF1 (hPIF1) is poorly understood, but its functions can become critical for tumour cell survival during oncogene-driven replication stress. Here we report the discovery, via an X-ray crystallographic fragment screen (XChem), of hPIF1 DNA binding and unwinding inhibitors. A structure was obtained with a 4-phenylthiazol-2-amine fragment bound in a pocket between helicase domains 2A and 2B, with additional contacts to Valine 258 from domain 1A. The compound makes specific interactions, notably through Leucine 548 and Alanine 551, that constrain conformational adjustments between domains 2A and 2B, previously linked to ATP hydrolysis and DNA unwinding. We next synthesized a range of related compounds and characterized their effects on hPIF1 DNA-binding and helicase activity in vitro, expanding the structure activity relationship (SAR) around the initial hit. A systematic analysis of clinical cancer databases is also presented here, supporting the notion that hPIF1 upregulation may represent a specific cancer cell vulnerability. The research demonstrates that hPIF1 is a tractable target through 4-phenylthiazol-2-amine derivatives as inhibitors of its helicase action, setting a foundation for creation of a novel class of anti-cancer therapeutics.

The immunomodulatory effects of vitamins in cancer.

Nutrition may affect animal health due to the strong link between them. Also, diets improve the healing process in various disease states. Cancer is a disease, where the harmful consequences of tumors severely impair the body. The information regarding the evolution of this disease is extrapolated from human to animal because there are few specific studies regarding nutritional needs in animals with cancer. Thus, this paper aims to review the literature regarding the immunomodulatory effects of vitamins in mammal cancer. An adequate understanding of the metabolism and requirements of nutrients for mammals is essential to ensuring their optimal growth, development, and health, regardless of their food sources. According to these: 1) Some species are highly dependent on vitamin D from food, so special attention must be paid to this aspect. Calcitriol/VDR signaling can activate pro-apoptotic proteins and suppress anti-apoptotic ones. 2) Nitric oxide (NO) production is modulated by vitamin E through inhibiting transcription nuclear factor kappa B (NF-κB) activation. 3) Thiamine supplementation could be responsible for the stimulation of tumor cell proliferation, survival, and resistance to chemotherapy. 4) Also, it was found that the treatment with NO-Cbl in dogs is a viable anti-cancer therapy that capitalizes on the tumor-specific properties of the vitamin B12 receptor. Therefore, diets should contain the appropriate class of compounds in adequate proportions. Also, the limitations of this paper are that some vitamins are intensively studied and at the same time regarding others, there is a lack of information, especially in animals. Therefore, some subsections are longer and more heavily debated than others.

Tumor microenvironment-activated polypeptide nanoparticles for oncolytic immunotherapy

Cationic oncolytic polypeptides have gained increasing attention owing to their ability to directly lyse cancer cells and activate potent antitumor immunity. However, the low tumor cell selectivity and inherent toxicity induced by positive charges of oncolytic polypeptides hinder their systemic application. Herein, a tumor microenvironment-responsive nanoparticle (DNP) is developed by the self-assembly of a cationic oncolytic polypeptide (PLP) with a pH-sensitive anionic polypeptide via electrostatic interactions. After the formation of DNP, the positive charges of PLP are shielded. DNPs can keep stable in physiological conditions (pH 7.4) but respond to acidic tumor microenvironment (pH 6.8) to release oncolytic PLP. As a result, DNPs evoke potent immunogenic cell death by disrupting cell membranes, damaging mitochondria and increasing intracellular levels of reactive oxygen species. In vivo results indicate that DNPs significantly improve the biocompatibility of PLP, and inhibit tumor growth, recurrence and metastasis by direct oncolysis and activation of antitumor immune responses. In summary, these results indicate that pH-sensitive DNPs represent a prospective strategy to improve the tumor selectivity and biosafety of cationic polymers for oncolytic immunotherapy.

B-328 A Novel Pathway of Akt-Dependent PARP1 Activation Through the Nuclear Localization of EPRS1

Abstract Background Glutamyl-prolyl-tRNA synthetase (EPRS1) is the only bifunctional aminoacyl-tRNA synthetase (aaRS) and is essential for interpreting the genetic code. EPRS1, along with seven other aaRSs, forms the multi-tRNA synthetase complex (MSC). EPRS1 consists of two catalytic domains, GluRS and ProRS, connected by a linker region. Several aaRSs within the MSC, including EPRS1, can dissociate from the MSC in response to specific stimuli. This dissociation enables non-canonical activities distinct from their primary role in protein synthesis. Breast cancer cells harboring a loss-of-function mutation in phosphatase and tensin homolog (PTEN) are known to have more activity in the serine/threonine kinase Akt. Poly-(ADP)-ribose polymerase 1 (PARP1), plays a vital role in DNA damage repair (DDR). PARP1 deposits one or more ADP-Ribose moieties onto damaged DNA or other proteins in a process referred to as PARylation. We hope to connect Akt activation and PARP1 activity through the nuclear localization and noncanonical function of EPRS1. We hypothesize, that when Akt is activated, either through the loss of PTEN function or through stimuli such as heat shock or H2O2 treatment, will stimulate the nuclear localization of EPRS1 and modulate PARP1 activity. Methods To test our hypothesis, we evaluate Akt activation, EPRS1 localization, and PARP1 activity. Using pharmacological activators and inhibitors of Akt, we test if inhibitors and activators alone are sufficient to cause the nuclear localization of EPRS1. Biochemically, we isolate nuclear and cytosolic fractions used in various western blot analysis. We use a variety of assays for PARP1 activity and DDR that include immobilized histones, calculating IC50s of PARP1 inhibitors, comet assay, and confocal microscopy. To ascertain the connection between PARP1 and EPRS1 we use LC-MS/MS analysis and immunoprecipitation. Results We show, in both patient-derived and cultured breast cancer cells, elevated levels of EPRS1 not only in the cytoplasm, but also within the nucleus. We find that nuclear localization EPRS1 is facilitated by a nuclear localization sequence (NLS) located within the linker region of the protein. Breast cancer cells harboring a loss-of-function in PTEN exhibit higher levels of EPRS1 in the nucleus compared to PTEN-positive cells. In EPRS1 knockdown cells, there is diminished expression of multiple tumor-related transcription factors, DNA-damage repair, tumor cell survival, and PARP1 auto-PARylation. We demonstrate that nuclear EPRS1 binds to and shares an interactome with PARP1. Conclusions EPRS1-mediated regulation of PARP1 activity provides a new mechanistic link between PTEN loss in breast cancer cells, PARP1 activation, and cell survival and tumor growth. Targeting the non-canonical activity of EPRS1, without inhibiting canonical tRNA ligase activity, might provide a new therapeutic approach in breast and other forms of cancer, potentially supplementing existing cancer therapeutics.

Enhancing CAR-T cell therapy against solid tumor by drug-free triboelectric immunotherapy

Chimeric antigen receptor (CAR) T cell therapy is a highly effective immunotherapy for hematological tumors, but its efficacy against most solid tumors remains challenging. Herein, a novel synergistic combination therapy of drug-free triboelectric immunotherapy and CAR-T cell therapy against solid tumor was proposed. A triboelectric nanogenerator (TENG) that can generate pulsed direct-current by coupling triboelectrification effect and electrostatic breakdown effect was fabricated. The TENG can generate up to 30 pulse direct-current peaks with peak current output ≈35 μA in a single sliding to power the triboelectric immunotherapy. The pulsed direct-current stimulation induced immunogenic cell death of tumor cells (survival rate of 35.9 %), which promoted dendritic cells maturation, accelerated the process of antigen presentation to CAR-T cells and enhanced the systemic adaptive immune response. Furthermore, triboelectric immunotherapy promoted M1-like macrophage polarization, reduced regulatory T cells differentiation and reprogrammed the tumor immunosuppressive microenvironment, which ultimately enhanced the efficacy of CAR-T cells to eradicate nearly 60 % of NALM6 solid tumor mass. Notably, considering that triboelectric immunotherapy is a safe and effective drug-free antitumor strategy, the combined therapy did not increase the burden of double-medication on patients.

Radiofrequency ablation: mechanisms and clinical applications.

Radiofrequency ablation (RFA), a form of thermal ablation, employs localized heat to induce protein denaturation in tissue cells, resulting in cell death. It has emerged as a viable treatment option for patients who are ineligible for surgery in various diseases, particularly liver cancer and other tumor-related conditions. In addition to directly eliminating tumor cells, RFA also induces alterations in the infiltrating cells within the tumor microenvironment (TME), which can significantly impact treatment outcomes. Moreover, incomplete RFA (iRFA) may lead to tumor recurrence and metastasis. The current challenge is to enhance the efficacy of RFA by elucidating its underlying mechanisms. This review discusses the clinical applications of RFA in treating various diseases and the mechanisms that contribute to the survival and invasion of tumor cells following iRFA, including the roles of heat shock proteins, hypoxia, and autophagy. Additionally, we analyze‌ the changes occurring in infiltrating cells within the TME after iRFA. Finally, we provide a comprehensive summary of clinical trials involving RFA in conjunction with other treatment modalities in the field of cancer therapy, aiming to offer novel insights and references for improving the effectiveness of RFA.

Detection of heat transfer mechanism in biological systems and HIF-1 α inducing invasion of liver cancer cells in hypoxic environments by activating STAT3

HIF-1α, as a hypoxia-inducing factor, can promote the invasion and metastasis of cancer cells by activating downstream signaling pathways. However, different heat transfer mechanisms in biological systems have important effects on the survival and function of tumor cells. The aim of this study was to investigate how the mechanisms of heat transfer in biological systems affect HIF-1α-mediated STAT3 activation and further induce the invasion ability of liver cancer cells in anoxic environment. The expression and activation of HIF-1α and STAT3 in hepatocellular carcinoma cell lines were detected by establishing anoxic model. At the same time, thermal imaging and heat transfer analysis methods were used to evaluate the heat transfer characteristics of cells under different temperature and hypoxia conditions. The effects of HIF-1α and STAT3 on invasion of hepatocellular carcinoma cells were analyzed in combination with cell migration and invasion experiments. The results showed that the expression of HIF-1α was significantly increased and the STAT3 signaling pathway was activated under hypoxia. The abnormal change of the heat transfer mechanism of biological system accelerates the invasion ability of hepatocellular carcinoma cells. Inhibition of HIF-1α expression can significantly reduce the activation level of STAT3, thereby inhibiting cell migration and invasion. This study reveals the interaction between the biological heat transfer mechanism and HIF-1α-STAT3 signaling pathway under hypoxia environment, which provides a new potential target for the treatment of malignant tumors such as liver cancer, and emphasizes the importance of regulating the heat transfer mechanism.

KRAS-Driven Tumorigenesis and KRAS-Driven Therapy in Pancreatic Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is associated with significant morbidity and mortality and is projected to be the second leading cause of cancer-related deaths by 2030. Mutations in KRAS are found in the vast majority of PDAC cases and plays an important role in the development of the disease. KRAS drives tumor cell proliferation and survival through activating the MAPK pathway to drive cell cycle progression and to lead to MYC-driven cellular programs. Moreover, activated KRAS promotes a protumorigenic microenvironment through forming a desmoplastic stroma and by impairing antitumor immunity. Secretion of granulocyte-macrophage colony-stimulating factor and recruitment of myeloid-derived suppressor cells and protumorigenic macrophages results in an immunosuppressive environment while secretion of secrete sonic hedgehog and TGFβ drive fibroblastic features characteristic of PDAC. Recent development of several small molecules to directly target KRAS marks an important milestone in precision medicine. Many molecules show promise in preclinical models of PDAC and in early phase clinical trials. In this review, we discuss the underlying cell intrinsic and extrinsic roles of KRAS in PDAC tumorigenesis, the pharmacologic development of KRAS inhibition, and therapeutic strategies to target KRAS in PDAC.

Dose-rate effects and tumor control probability in 177Lu-based targeted radionuclide therapy: a theoretical analysis

Objective.177Lu-based targeted radionuclide therapy (TRT) has become an important cancer treatment option in recent years, in particular in the treatment of advanced prostate cancer and metastasized neuroendocrine tumors. Although it is known from conventional radiotherapy that the temporal dynamics of the dose-rate can be of relevance for tumor cell survival, the analysis of TRT efficacy usually considers only the absorbed dose. Thus, the aim of this theoretical analysis is to shed light on the possible effects of the pattern of dose-rate in TRT on tumor control probability (TCP).Approach.For this purpose, TCP is studied numerically in a typical four-cycle treatment regime based on the mechanistic lethal-potentially lethal model and the Zaider-Minerbo model for TCP including repopulation of tumor cells.Main results.It is shown that the dose-rate pattern in TRT can have a substantial effect on TCP even though the absorbed dose in the tumor lesion is unchanged. These dose-rate effects are particularly evident when repair of potentially lethal lesions is slow.Significance.The results indicate that in some situations in the analysis of the efficacy of TRT it is necessary to consider the full dose-rate pattern instead of the absorbed dose alone. This can be highly relevant for optimization and further development of TRTs. In particular, it could be of relevancy in studying the efficacy of newly emerging treatment concepts that combine the use of TRT and drugs that inhibit DNA damage repair.

The Anticancer Properties, Cell-cycle Cytotoxicity and Apoptosis of Cissus rotundifolia, Trema orientalis, and Buddleja polystachya with Ocular Applications

BackgroundBuddleja polystachya, Trema orientalis, and Cissus rotundifolia were applied locally for various ocular purposes, while receiving few scientific evaluations. PurposeThis study aimed to screen the anticancer properties and determine the cell-cycle cytotoxicity and apoptotic activity of the most promising plant extract. MethodsIn this study, MTT assays with MCF7 (human breast adenocarcinoma), HT29 (human colorectal adenocarcinoma) and HepG2 (human liver adenocarcinoma) were used. In addition to MRC5 (normal human foetal lung fibroblast) was carried out for preliminary activity screening and selectivity. The most promising extract was subjected to GC-MS analysis to determine the phytochemical composition. Additionally, a clonogenic assay was performed to measure tumor cell survival and subsequent proliferative capacity after drug exposure was conducted for the most active extract(s) and finally western blotting was used to determine the expression change of the two selected proteins (survivin and CCND1) in order to determine the exact mechanistic features of the most promising plant extract. ResultsThe six extracts showed variable IC50 values ranging from 1.77- 40.97 μg/mL. The most active extracts were C. rotundifolia coded as (stem; BEP-03A and leaves; BEP-03B) on HepG2 cells and showed ∼ 4 and 8 fold selectivity compared to normal MRC5 cells. Both extracts showed a dose-dependent clonogenic effect on HepG2 cells, which was comparable to the effect of doxorubicin. The extract (BEP-03B) caused a significant decrease in the expression of survivin and CCND1 compared to the control GAPDH at its highest dose (12 µg/mL). The GC-MS chromatogram of the leaf of C. rotundifolia extract (BEP-03B) revealed the presence of 17 compounds, as the main phytoconstituents representing 57.5% of the total compounds present in BEP-03B. Three steroidal components (12, 14 and 15) were the main components, while compound stigmast-5-en-3-ol (compound 15) was the main component. ConclusionsLeaves of Cissus rotundifolia (Forssk.) Vahl, possess a significant cytotoxic effect and it may produce this effect, through apoptosis induction, perturbation, and disruption of the cell cycle. The detected phytoconstituents in the plant extract might be involved in the tested cytotoxic activity and its molecular apoptotic mechanism. Future studies are required to isolate the active ingredient(s) and confirm the therapeutic application(s).

Time to heal: inhibiting fibrosis prevents glioblastoma recurrence

New findings by Walson et al. demonstrate that therapy-induced inflammation and fibrosis potentiate glioblastoma recurrence. Post-treatment fibrotic niches shielded surviving tumor cells from immune surveillance, supported their persistence in a dormant state, and enabled rebound growth. Timely inhibition of inflammation and scarring attenuated recurrence, encouraging the use of new combinatorial approaches in glioblastoma therapy.

Gremlin1: a BMP antagonist with therapeutic potential in Oncology.

Gremlins, originating from early 20th-century Western folklore, are mythical creatures known for causing mechanical malfunctions and electronic failures, aptly dubbed "little devils". Analogously, GREM1 acts like a horde of these mischievous entities by antagonizing the bone morphogenetic protein (BMP signaling) pathway or through other non-BMP dependent mechanisms (such as binding to Fibroblast Growth Factor Receptor 1and Epidermal Growth Factor Receptor) contributing to the malignant progression of various cancers. The overexpression of GREM1 promotes tumor cell growth and survival, enhances angiogenesis within the tumor microenvironment, and creates favorable conditions for tumor development and dissemination. Consequently, inhibiting the activity of GREM1 or blocking its interaction with BMP presents a promising strategy for suppressing tumor growth and metastasis. However, the role of GREM1 in cancer remains a subject of debate, with evidence suggesting both oncogenic and tumor-suppressive functions. Currently, several pharmaceutical companies are researching the GREM1 target, with some advancing to Phase I/II clinical trials. This article will provide a detailed overview of the GREM1 target and explore its potential role in cancer therapy.

Spatial interactions modulate tumor growth and immune infiltration

Direct observation of tumor-immune interactions is unlikely in tumors with currently available technology, but computational simulations based on clinical data can provide insight to test hypotheses. It is hypothesized that patterns of collagen evolve as a mechanism of immune escape, but the exact nature of immune-collagen interactions is poorly understood. Spatial data quantifying collagen fiber alignment in squamous cell carcinomas indicates that late-stage disease is associated with highly aligned fibers. Our computational modeling framework discriminates between two hypotheses: immune cell migration that moves (1) parallel or (2) perpendicular to collagen fiber orientation. The modeling recapitulates immune-extracellular matrix interactions where collagen patterns provide immune protection, leading to an emergent inverse relationship between disease stage and immune coverage. Here, computational modeling provides important mechanistic insights by defining a kernel cell-cell interaction function that considers a spectrum of local (cell-scale) to global (tumor-scale) spatial interactions. Short-range interaction kernels provide a mechanism for tumor cell survival under conditions with strong Allee effects, while asymmetric tumor-immune interaction kernels lead to poor immune response. Thus, the length scale of tumor-immune interaction kernels drives tumor growth and infiltration.

Abstract C016: Optical Techniques to Democratize Intravital Quantification of Metabolic Heterogeneity

Abstract Since metabolic and vascular adaptations are essential for tumor cell survival, a technique capable of tracking metabolic heterogeneity at both the bulk tumor and cellular scales over extended timelines is necessary. To address this technological need, we have developed a multi-scale optical microscope relying on exogenous fluorescent reporters for dynamic spatiotemporal imaging of major metabolic pathways in vivo. This microscope utilizes a low-cost CMOS detector and LEDs for excitation to enable fluorescence microscopy in resource-limited settings. Here, we implement our system to assess changes in bulk tumor and cellular metabolic heterogeneity as vasculature is perturbed. 4T1 breast tumor-bearing mice were treated with combretastatin A-1 (a vascular disruptor), implanted with window chambers, and temporally imaged (n=5/group). Fluorescence imaging and Gabor filter/Djikstra segmentation approaches enabled metabolic and vascular analyses, respectively. We demonstrated the system’s ability to acquire co-registered images of vasculature, morphology, and distinct metabolic endpoints reporting on glucose uptake, fatty acid uptake, and mitochondrial metabolism at both wide-field and high resolutions. At 12 hours post-treatment, the tumors’ metabolism shifted from mitochondrial respiration to glycolysis in avascular regions. Further, we report a higher average vascular density in untreated versus treated mice at 108 hours post-treatment (p<0.05, Kolmogorov-Smirnov test). On exploring the relationship between metabolic activity and vasculature, regions with high local tortuosity in the untreated group exhibited a higher reliance on fatty acid uptake than high tortuosity regions in the treatment group, indicating these cells’ reliance on fatty acids within a complex vascular network. Our multiplexed imaging strategy enables the quantification of tumor metabolism and vasculature over multiple length scales, which could be leveraged to study adaptations following clinical therapies. Citation Format: Enakshi Sunassee. Optical Techniques to Democratize Intravital Quantification of Metabolic Heterogeneity [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C016.