Promotes Cancer Cell Proliferation Research Articles

Calreticulin-Driven Autophagy Enhances Cell Proliferation in laryngeal Squamous Cell Carcinoma

BackgroundCalreticulin (CALR) is a multifunctional calcium-binding protein. Recent studies have revealed that CALR contributes to tumor development and promotes cancer cell proliferation. However, how CALR affects the development of laryngeal squamous cell carcinoma (LSCC) remains mysterious. Thus, this study aimed to explore the effect of CALR on LSCC development and uncover its underlying mechanisms. MethodsCALR expression in LSCC cell lines and tissues was examined by qRT-PCR and western blot analysis and its functional role was detected via in vivo and in vitro assays. Cell proliferation was discriminated with CCK-8 and colony formation assays, while apoptosis was analyzed using flow cytometry. Autophagy levels were measured via LC3 immunofluorescence, and western blot assay was conducted to assess apoptosis- and autophagy-related proteins. Additionally, a mouse xenograft model was employed to determine the impact of CALR knockdown on tumor growth. ResultsWe found that CALR knockdown reduced LSCC cell viability and proliferation while enhancing apoptosis, whereas CALR overexpression showed opposite effects. In vivo experiments verified that CALR knockdown suppressed tumor growth. In addition, elevated CALR expression induced autophagy in LSCC cells, while autophagy inhibitor 3-MA (2.5mM) reversed the anti-apoptosis effects of CALR overexpression. ConclusionOur study identifies CALR as an oncogene in LSCC, where it promotes tumor progression by inducing autophagy and inhibiting apoptosis. Targeting CALR or modulating autophagy may represent novel therapeutic strategies for LSCC.

LncRNAs in tumor metabolic reprogramming and tumor microenvironment remodeling.

The tumor microenvironment (TME) is a complex and dynamic ecosystem composed of tumor cells, immune cells, supporting cells, and the extracellular matrix. Typically, the TME is characterized by an immunosuppressive state. To meet the demands of rapid proliferation, cancer cells undergo metabolic reprogramming, which enhances their biosynthesis and bioenergy supply. Immune cells require similar nutrients for activation and proliferation, leading to competition and immunosuppression within the TME. Additionally, tumor metabolites inhibit immune cell activation and function. Consequently, an immunosuppressed and immune-tolerant TME promotes cancer cell proliferation and metastasis. Long non-coding RNAs (lncRNAs), a category of non-coding RNA longer than 200 nucleotides, regulate tumor metabolic reprogramming by interacting with key enzymes, transporters, and related signaling pathways involved in tumor metabolism. Furthermore, lncRNAs can interact with both cellular and non-cellular components in the TME, thereby facilitating tumor growth, metastasis, drug resistance, and inducing immunosuppression. Recent studies have demonstrated that lncRNAs play a crucial role in reshaping the TME by regulating tumor metabolic reprogramming. In this discussion, we explore the potential mechanisms through which lncRNAs regulate tumor metabolic reprogramming to remodel the TME. Additionally, we examine the prospects of lncRNAs as targets for anti-tumor therapy and as biomarkers for tumor prognosis.

Mesoporous Biosilica Beads for Controlled Selenium Nanoparticle Delivery from Collagen‐Chitosan Scaffolds: Promoting Bone Formation and Suppressing Prostate Cancer Growth

The controlled delivery of selenium nanoparticles (Se‐NPs) is promising for bone cancer treatment due to their dual benefits in bone regeneration and tumor inhibition, yet achieving an optimal dosing regimen remains challenging. Natural mesoporous biosilica (BS) beads have shown promise for drug delivery due to their microporous structure. This study explores incorporating BS beads into collagen‐chitosan (Coll‐CS) scaffolds, known for bone repair, to control Se‐NP delivery. Two approaches are compared: loading Se‐NPs into BS beads before integrating them into Coll‐CS scaffolds versus directly loading Se‐NPs into Coll‐CS scaffolds. The scaffold properties, Se release kinetics, cytocompatibility, and effects on mesenchymal stem cells (MSCs) and prostate cancer cells (LNCaP) are evaluated. BS bead‐loaded scaffolds provide controlled Se‐NP release and enhanced mechanical properties compared to directly loaded scaffolds. Higher Se‐NP concentrations in BS‐loaded scaffolds effectively promote MSC osteogenic differentiation and mineralisation while inhibiting LNCaP cell viability. In contrast, low Se‐NP concentrations not only induce early osteogenic differentiation but also promote cancer cell proliferation, underscoring the need for optimal Se‐NP concentration and release. These findings suggest that BS bead‐loaded Coll‐CS scaffolds are a promising strategy for controlled Se‐NP delivery, addressing the dual challenges of bone formation and cancer recurrence prevention in bone cancer treatment.

Impact of MTHFD2 Expression in Bladder/Breast Cancer and Screening of Its Potential Inhibitor.

Genes of folate-mediated 1 carbon metabolism are found to be highly upregulated in tumor cells and promote cancer cell proliferation. The current study aimed to determine the expression of the MTHFD2 gene in bladder and breast cancers. Furthermore, the determination of potential ligand-based inhibitors against MTHFD2 was performed in comparison with those of chemotherapeutic drugs and natural plant-based compounds. Semiquantitative expression analysis along with structure-based virtual ligand library screening was done to find plausible inhibitors. MTHFD2 expression was significantly increased with tumor stage progression both in low- and high-grade bladder cancer and especially in triple-negative breast cancer. Virtual ligand-based library screening against the three-dimensional MTHFD2 protein structure led to the identification of plausible inhibitors like MCULE-8109969891-0 and MCULE-9715677418-0-1 that displayed lower binding free energy as compared to that of already documented LY345899. Similar scaffold commercial drugs leucal (LEU), epirubicin (EPI), and lometrexol also displayed strong binding to the active site of MTHFD2. EPI and LEU in combinatorial therapy were also tested in vitro on MDA-MB-231 cells. The high doses of LEU in combination with EPI showed a significant reduction in cell viability at 2 and 3 μM concentrations. The interaction of breast cancer serum with high expression of MTHFD2 also showed an increase in binding of epirubicin in the presence of leucovorin. The decrease in the absorbance spectra of epirubicin at 37 and 53 °C displayed the stability induced by LEU on the interaction of EPI with the MTHFD2 binding pocket. Leucovorin tends to stabilize the interaction as the binding affinity is high even at 53 °C. Thus, MTHFD2 might be used as a cancer biomarker since its expression level changes drastically with tumor progression. Further experimental studies are required to establish the potential mode of inhibition of the novel small ligands. Future in vivo trials may validate the effectiveness of the combinatorial therapy.

Expression of Concern: Overexpression of HMGA2 in breast cancer promotes cell proliferation, migration, invasion and stemness

Expression of Concern: Overexpression of HMGA2 in breast cancer promotes cell proliferation, migration, invasion and stemness

Branched-chain amino acid catabolism promotes ovarian cancer cell proliferation via phosphorylation of mTOR.

This study uncovers altered amino acid metabolism, specifically increased BCAA catabolism, at the interface of ovarian cancer cells and omental tissue in a coculture model of HGSOC secondary metastasis. Enhanced BCAA catabolism may promote cancer cell proliferation through mTOR signaling, presenting potential therapeutic value. These findings deepen our understanding of HGSOC pathogenesis and the metastatic tumor microenvironment, offering insights for developing new treatment strategies.

BANF1 is a novel prognostic biomarker linked to immune infiltration in head and neck squamous cell carcinoma.

Barrier-to-autointegration factor 1 (BANF1) is an abundant and ubiquitously expressed postnatal mammalian protein that is overexpressed in numerous human cancers and can promote cancer cell proliferation. However, the role of BANF1 in prognosis remains unclear in head and neck squamous cell carcinoma (HNSCC). BANF1 expression data were obtained from the GEO and TCGA databases. We used Cox regression and Kaplan-Meier curves to assess the prognostic potential of BANF1. The role of BANF1-related genes was investigated using Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analyses. In addition, we explored the link between BANF1, drug sensitivity, and the tumor immune microenvironment. Finally, functional in vitro and in vivo assays were used to explore the effects of BANF1 on tumor growth and metastasis of HNSCC. BANF1 was markedly overexpressed in HNSCC and was correlated with clinicopathological characteristics. According to survival analysis, BANF1 can be inversely correlated with patient survival and can act as a prognostic risk indicator. IC50 values for chemotherapeutic treatments indicated that the group with high BANF1 expression was more responsive to most antitumor treatments. Furthermore, higher TIDE scores were observed in the low BANF1 expression group, indicating a decline in the efficacy of immune checkpoint inhibitor therapy. Functionally, the malignant biological behavior of HNSCC cell lines was inhibited when BANF1 expression was knocked down. BANF1 can promote tumor progression in patients with HNSCC. BANF1 shows great promise as a potential biomarker to assess the prognosis.

In Silico Approach for Assessment of the Anti-Tumor Potential of Cannabinoid Compounds by Targeting Glucose-6-Phosphate Dehydrogenase Enzyme.

Glucose-6-phosphate dehydrogenase (G6PD) is a pentose phosphate pathway (PPP) enzyme that generates NADPH, which is required for cellular redox equilibrium and reductive biosynthesis. It has been demonstrated that abnormal G6PD activation promotes cancer cell proliferation and metastasis. To date, no G6PD inhibitor has passed clinical testing successfully enough to be launched as a medicine. As a result, in this investigation, cannabinoids were chosen to evaluate their anticancer potential by targeting G6PD. Molecular docking indicated that three molecules, Tetrahydrocannabinolic acid (THCA), Cannabichromenic acid (CBCA), and tetrahydrocannabivarin (THCV), have the highest binding affinities for G6PD of -8.61, -8.39, and 8.01 Kcal mol. ADMET analysis found that all of them were safe prospective drug candidates. Molecular dynamics (MD) simulation and MM-PBSA analysis confirm the structural compactness and lower conformational variation of protein-ligand complexes, thereby maintaining structural stability and rigidity. Thus, our in silico investigation exhibited all three cannabinoids as potential competitive inhibitors of G6PD.

Oncogenic accumulation of cysteine promotes cancer cell proliferation by regulating the translation of D-type cyclins

Malignant cells exhibit a high demand for amino acids to sustain their abnormal proliferation. Particularly, the intracellular accumulation of cysteine is often observed in cancer cells. Previous studies have shown that deprivation of intracellular cysteine in cancer cells results in the accumulation of lipid peroxides in the plasma membrane and induction of ferroptotic cell death, indicating that cysteine plays a critical role in the suppression of ferroptosis. Herein, we found that the oncogenic accumulation of cysteine also contributes to cancer cell proliferation by promoting the cell cycle progression, which is independent of its suppressive effect on ferroptosis. The growth ability of four types of cancer cells, including murine hepatocarcinoma cells, but not of primary hepatocytes, were dependent on the exogenous supply of cysteine. Deprivation of intracellular cysteine in cancer cells induced cell cycle arrest at the G0/G1 phase, accompanied by a decrease in the expression of cyclin D1 and D2 proteins. The cysteine deprivation-induced decrease in D-type cyclin expression was associated with the upregulation of eukaryotic translation initiation factor 4E binding protein (4E-BP1), which represses the translation of cyclin D1 and D2 proteins by binding to eukaryotic translation initiation factor 4E (eIF4E). Similar results were observed in hepatocarcinoma cells treated with erastin, an xCT inhibitor. These findings reveal an unappreciated role of cysteine in regulating the growth of malignant cancer cells and deepen our understanding of the cytotoxic effect of xCT inhibitor to prevent cancer cell proliferation.

Circular RNA-encoded oncogenic PIAS1 variant blocks immunogenic ferroptosis by modulating the balance between SUMOylation and phosphorylation of STAT1

BackgroundThe clinical response rate to immune checkpoint blockade (ICB) therapy in melanoma remains low, despite its widespread use. Circular non-coding RNAs (circRNAs) are known to play a crucial role in cancer progression and may be a key factor limiting the effectiveness of ICB treatment.MethodsThe circRNAs that were downregulated after coadministration compared with single administration of PD-1 inhibitor administration were identified through RNA-seq and Ribo-seq, and thus the circPIAS1 (mmu_circ_0015773 in mouse, has_circ_0008378 in human) with high protein coding potential was revealed. Fluorescence in situ hybridization (FISH) assays were conducted to determine the localization of circPIAS1 in human and mouse melanoma cells, as well as its presence in tumor and adjacent tissues of patients. Validation through dual-luciferase reporter assay and LC–MS/MS confirmed the ability of circPIAS1 to encode a novel 108 amino acid polypeptide (circPIAS1-108aa). Specific antisense oligonucleotides (ASOs) targeting the junction site of circPIAS1 were developed to reduce its intracellular levels. Proliferation changes in melanoma cells were assessed using CCK8, EdU, and colony formation assays. The impact of circPIAS1-108aa on the ferroptosis process of melanoma cells was studied through GSH, MDA, and C11-BODIPY staining assays. Western Blot, Immunoprecipitation (IP), and Immunoprecipitation-Mass Spectrometry (IP-MS) techniques were employed to investigate the impact of circPIAS1-108aa on the P-STAT1/SLC7A11/GPX4 signaling pathway, as well as its influence on the balance between STAT1 SUMOylation and phosphorylation. Additionally, a melanoma subcutaneous transplanted tumor mouse model was utilized to examine the combined effect of reducing circPIAS1 levels alongside PD-1 inhibitor.ResultsCompared with the group treated with PD-1 inhibitor alone, circPIAS1 was significantly down-regulated in the coadministration group and demonstrated higher protein coding potential. CircPIAS1, primarily localized in the nucleus, was notably upregulated in tumor tissues compared to adjacent tissues, where it plays a crucial role in promoting cancer cell proliferation. This circRNA can encode a unique polypeptide consisting of 108 amino acids, through which it exerts its cancer-promoting function and impedes the effectiveness of ICB therapy. Mechanistically, circPIAS1-108aa hinders STAT1 phosphorylation by recruiting SUMO E3 ligase Ranbp2 to enhance STAT1 SUMOylation, thereby reactivating the transduction of the SLC7A11/GPX4 signaling pathway and restricting the immunogenic ferroptosis induced by IFNγ. Furthermore, the combination of ASO-circPIAS1 with PD-1 inhibitor effectively inhibits melanoma growth and significantly enhances the efficacy of immune drugs in vivo.ConclusionsOur study uncovers a novel mechanism regarding immune evasion in melanoma driven by a unique 108aa peptide encoded by circPIAS1 in melanoma that dramatically hinders immunogenic ferroptosis triggered by ICB therapy via modulating the balance between SUMOylation and phosphorylation of STAT1. This work reveals circPIAS1-108aa as a critical factor limiting the immunotherapeutic effects in melanoma and propose a promising strategy for improving ICB treatment outcomes.

E242-E261 region of MYC regulates liquid-liquid phase separation and tumor growth by providing negative charges

MYC is one of the most extensively studied oncogenic proteins and is closely associated with the occurrence and progression of many tumors. Previous studies have shown that MYC regulates cell fate through its liquid-liquid phase separation (LLPS) mechanism, which is dependent on two disordered domains within its N-terminal transcriptional activation regions. In this study, we revealed that the negatively charged conserved region (E242-E261) of the MYC protein controls its condensation formation and irreversible aggregation through multivalent electrostatic interactions (MEIs). Furthermore, deletion or mutation of the E242-E261 amino acids in the MYC protein enhances the transcriptional function of MYC by altering its aggregation capacity and subsequently promoting cancer cell proliferation. The discovery of the negatively charged region and its regulatory action on the phase separation of MYC provides a new understanding on the aggregation and function of MYC.

Multicenter cohort analysis of anoikis and EMT: implications for prognosis and therapy in lung adenocarcinoma

BackgroundAnoikis and epithelial-mesenchymal transition (EMT) are pivotal in the distant metastasis of lung adenocarcinoma (LUAD). A detailed understanding of their interplay and the identification of key genes is vital for effective therapeutic strategies against LUAD metastasis.MethodsKey prognostic genes related to anoikis and EMT were identified through univariate Cox regression analysis. We utilized ten machine learning algorithms to develop the Anoikis and EMT-Related Optimal Model (AEOM). The TCGA-LUAD dataset served as the training cohort, while six additional international multicenter LUAD datasets were employed as validation cohorts. The average concordance index (c-index) was used to evaluate model performance and identify the most effective model. Subsequent multi-omics analyses were conducted to explore differences in pathway enrichment, immune infiltration, and mutation landscapes between high and low AEOM groups. Experimental validation demonstrated that RHPN2, a key biomarker within the model, acts as an oncogene facilitating LUAD progression.ResultsThe AEOM displayed superior prognostic predictive performance for LUAD patients, outperforming numerous previously published LUAD signatures. Biologically, the AEOM was notably associated with immune features; the high AEOM group exhibited decreased immune activity and a tendency towards immune-cold tumors, as well as a higher tumor mutational burden (TMB). Subgroup analysis revealed that the low AEOM + high TMB group had the most favorable prognosis. The high AEOM group was primarily enriched in cell cycle-related pathways, promoting cancer cell proliferation. RHPN2, a crucial gene within the AEOM (correlation = 0.85, P < 0.05), was linked to poorer prognosis in LUAD patients with elevated RHPN2 expression. Further in vitro experiments showed that RHPN2 modulates LUAD cell proliferation and invasion.ConclusionThe AEOM provides a robust prognostic model for LUAD, uncovering critical immune and biological pathways, with RHPN2 identified as a key oncogenic driver. These findings offer valuable insights for targeted therapies and enhanced patient outcomes.

Unlocking the tumor-immune microenvironment in osteosarcoma: insights into the immune landscape and mechanisms.

Osteosarcoma has a unique tumor microenvironment (TME), which is characterized as a complex microenvironment comprising of bone cells, immune cells, stromal cells, and heterogeneous vascular structures. These elements are intricately embedded in a mineralized extracellular matrix, setting it apart from other primary TMEs. In a state of normal physiological function, these cell types collaborate in a coordinated manner to maintain the homeostasis of the bone and hematopoietic systems. However, in the pathological condition, i.e., neoplastic malignancies, the tumor-immune microenvironment (TIME) has been shown to promote cancer cells proliferation, migration, apoptosis and drug resistance, as well as immune escape. The intricate and dynamic system of the TIME in osteosarcoma involves crucial roles played by various infiltrating cells, the complement system, and exosomes. This complexity is closely associated with tumor cells evading immune surveillance, experiencing uncontrolled proliferation, and facilitating metastasis. In this review, we elucidate the intricate interplay between diverse cell populations in the osteosarcoma TIME, each contributing uniquely to tumor progression. From chondroblastic and osteoblastic osteosarcoma cells to osteoclasts, stromal cells, and various myeloid and lymphoid cell subsets, the comprehensive single-cell analysis provides a detailed roadmap of the complex osteosarcoma ecosystem. Furthermore, we summarize the mutations, epigenetic mechanisms, and extracellular vesicles that dictate the immunologic landscape and modulate the TIME of osteosarcoma. The perspectives of the clinical implementation of immunotherapy and therapeutic approaches for targeting immune cells are also intensively discussed.

Adipocyte derived exosomes promote cell invasion and challenge paclitaxel efficacy in ovarian cancer

BackgroundEpithelial ovarian cancer (EOC) is the deadliest gynaecological cancer with high mortality rates driven by the common development of resistance to chemotherapy. EOC frequently invades the omentum, an adipocyte-rich organ of the peritoneum and omental adipocytes have been implicated in promoting disease progression, metastasis and chemoresistance. The signalling mechanisms underpinning EOC omentum tropism have yet to be elucidated.MethodsThree-dimensional co-culture models were used to explore adipocyte-EOC interactions. The impact of adipocytes on EOC proliferation, response to therapy and invasive capacity was assessed. Primary adipocytes and omental tissue were isolated from patients with ovarian malignancies and benign ovarian neoplasms. Exosomes were isolated from omentum tissue conditioned media and the effect of omentum-derived exosomes on EOC evaluated. Exosomal microRNA (miRNA) sequencing was used to identify miRNAs abundant in omental exosomes and EOC cells were transfected with highly abundant miRNAs miR-21, let-7b, miR-16 and miR-92a.ResultsWe demonstrate the capacity of adipocytes to induce an invasive phenotype in EOC populations through driving epithelial-to-mesenchymal transition (EMT). Exosomes secreted by omental tissue of ovarian cancer patients, as well as patients without malignancies, induced proliferation, upregulated EMT markers and reduced response to paclitaxel therapy in EOC cell lines and HGSOC patient samples. Analysis of the omentum-derived exosomes from cancer patients revealed highly abundant miRNAs that included miR-21, let-7b, miR-16 and miR-92a that promoted cancer cell proliferation and protection from chemotherapy when transfected in ovarian cancer cells.ConclusionsThese observations highlight the capacity of omental adipocytes to generate a pro-tumorigenic and chemoprotective microenvironment in ovarian cancer and other adipose-related malignancies.

Knockdown of PAIP1 Inhibits Breast Cancer Cell Proliferation by Regulating Cyclin E2 mRNA Stability.

Polyadenylate-binding protein-interacting protein 1 (PAIP1) is a protein that modulates translation initiation in eukaryotic cells. Studies have shown that PAIP1 was overexpressed in various type of cancers, and drives cancer progression by promoting cancer cell proliferation, invasion, and migration. In our previous study, we identified that PAIP1 was overexpressed in breast cancer, and the expression was correlated with poor prognosis. However, the biological function of PAIP1 in breast cancer has not been clearly understood. In this study, we constructed PAIP1 specifically silenced breast cancer cells. Then, cell proliferation, cell cycle distribution, and apoptosis were detected in PAIP1 knockdown cells. RNA-seq analysis was performed to predict the downstream target of PAIP1, and the molecular mechanism was explored. As a results, we found that knockdown of PAIP1 repressed cell proliferation, induced cell cycle arrest, and triggers apoptosis. Xenograft mouse model showed that knockdown of PAIP1 inhibits cell growth in vivo. RNA-seq predicted that CCNE2 mRNA was one of the downstream targets of PAIP1. In addition, we identified that knockdown of PAIP1-inhibited cell proliferation through modulating cyclin E2 expression. Mechanically, knockdown of PAIP1 reduces the expression of cyclin E2 by regulating the mRNA stability of cyclin E2. Moreover, in breast cancer tissues, we found that the expression of PAIP1 was positively correlated with cyclin E2. Taken together, our findings establish the role and mechanism of PAIP1 in breast cancer progression, indicating that PAIP1 would be a new therapeutic target for breast cancer treatment.

Analyzing the role of TM4SF1 expression in pancreatic adenocarcinoma: understanding prognostic implications and therapeutic opportunities.

Pancreatic adenocarcinoma (PAAD) is a highly lethal malignancy characterized by aggressive growth and poor prognosis. Understanding the molecular mechanisms underlying PAAD is crucial for developing effective therapies. This study aimed to explore the role of TM4SF1 and other key genes in PAAD progression, their prognostic implications, and therapeutic opportunities. Differential gene expression analysis was performed using PAAD and normal tissue samples to identify upregulated genes, with TM4SF1 emerging as significantly elevated in PAAD. Functional enrichment analysis elucidated associated signaling pathways. A prognostic model comprising BPIFB4, PLEKHN1, CPTP, DVL1, and DDR1 was developed using least absolute shrinkage and selection operator (LASSO) regression and validated in an independent cohort. Genetic mutation analysis provided insights into the functional significance of identified genes. Pharmacogenomic analysis examined associations between gene expression and drug sensitivity. Experimental validation included quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot analyses to confirm gene expression patterns and protein levels. Lower TM4SF1 expression correlated with enhanced anti-tumor immune activity in PAAD, suggesting a complex interplay between genetic expression and immune response. The prognostic model showed robust associations with patient survival outcomes, validated across diverse patient cohorts. Genetic mutation analysis highlighted potential therapeutic targets. Pharmacogenomic analysis revealed correlations between gene expression profiles and drug responsiveness, suggesting personalized treatment strategies. Experimental validation confirmed elevated TM4SF1 levels in tumor tissues and demonstrated its role in promoting cancer cell proliferation and colony formation. This study advances understanding of the molecular landscape of PAAD, emphasizing TM4SF1 as a key regulator and potential therapeutic target. The integration of genetic expression, immune response dynamics, and pharmacogenomics offers a multifaceted approach to personalized treatment strategies for PAAD, paving the way for improved patient outcomes and novel therapeutic interventions. Further research is warranted to elucidate the clinical utility of targeting TM4SF1 and other identified genes in PAAD management.

Antagonist anti-LIF antibody derived from naive human scFv phage library inhibited tumor growth in mice

BackgroundLeukemia inhibitory factor (LIF) is a multifunctional member of the IL-6 cytokine family that activates downstream signaling pathways by binding to the heterodimer consisting of LIFR and gp130 on the cell surface. Previous research has shown that LIF is highly expressed in various tumor tissues (e.g. pancreatic cancer, breast cancer, prostate cancer, and colorectal cancer) and promotes cancer cell proliferation, migration, invasion, and differentiation. Moreover, the overexpression of LIF correlates with poor clinicopathological characteristics. Therefore, we hypothesized that LIF could be a promising target for the treatment of cancer. In this work, we developed the antagonist antibody 1G11 against LIF and investigated its anti-tumor mechanism and its therapeutic efficacy in mouse models.ResultsA series of single-chain variable fragments (scFvs) targeting LIF were screened from a naive human scFv phage library. These scFvs were reconstructed in complete IgG form and produced by the mammalian transient expression system. Among the antibodies, 1G11 exhibited the excellent binding activity to human, cynomolgus monkey and mouse LIF. Functional analysis demonstrated 1G11 could block LIF binding to LIFR and inhibit the intracellular STAT3 phosphorylation signal. Interestingly, 1G11 did not block LIF binding to gp130, another LIF receptor that is involved in forming the receptor complex together with LIFR. In vivo, intraperitoneal administration of 1G11 inhibited tumor growth in CT26 and MC38 models of colorectal cancer. IHC analysis demonstrated that p-STAT3 and Ki67 were decreased in tumor tissue, while c-caspase 3 was increased. Furthermore, 1G11 treatment improves CD3+, CD4 + and CD8 + T cell infiltration in tumor tissue.ConclusionsWe developed antagonist antibodies targeting LIF/LIFR signaling pathway from a naive human scFv phage library. Antagonist anti-LIF antibody exerts antitumor effects by specifically reducing p-STAT3. Further studies revealed that anti-LIF antibody 1G11 increased immune cell infiltration in tumor tissues.

METTL5: A Potential Biomarker for Nonsmall Cell Lung Cancer That Promotes Cancer Cell Proliferation by Interacting with IGF2BP3.

Objective: To examine if METTL5 promotes the proliferation of nonsmall cell lung cancer (NSCLC) cells by interacting with IGF2BP3. Methods: The expression patterns of METTL5 and IGF2BP3 in NSCLC tissues, their relationship with survival rate, and their correlation were analyzed using bioinformatics and clinical sample analyses. The effects of METTL5 overexpression and IGF2BP3 knockdown, as well as those of METTL5 knockdown and IGF2BP3 overexpression, on the proliferation of NSCLC cells were analyzed by transfecting appropriate constructs. The interaction between METTL5 and IGF2BP3 was verified using the co-immunoprecipitation (Co-IP) assay. The invivo effects of METTL5 and IGF2BP3 on NSCLC growth were analyzed using the tumor-bearing nude mouse model. Results: METTL5 and IGF2BP3 expression levels were positively correlated and were associated with poor clinical prognosis. The METTL5 and IGF2BP3 expression levels were upregulated in the clinical NSCLC samples. IGF2BP3 expression did not affect METTL5 expression but was regulated by METTL5. IGF2BP3 overexpression mitigated the METTL5 knockdown-induced impaired cell proliferation. Meanwhile, IGF2BP3 knockdown suppressed METTL5-mediated NSCLC cell proliferation. The Co-IP assay results revealed the interaction between METTL5 and IGF2BP3 in NSCLC cells. IGF2BP3 knockdown suppressed tumor growth, whereas IGF2BP3 overexpression enhanced tumor volume and quality. Conclusion: METTL5 induces NSCLC cell proliferation by interacting with IGF2BP3. Thus, METTL5 is a potential biomarker and a therapeutic target for NSCLC.

High-motility pro-tumorigenic monocytes drive macrophage enrichment in the tumor microenvironment.

Enrichment of tumor-associated macrophages (TAMΦs) in the tumor microenvironment correlates with worse clinical outcomes in triple-negative breast cancer (TNBC) patients, prompting the development of therapies to inhibit TAMΦ infiltration. However, the lackluster efficacy of CCL2-based chemotaxis blockade in clinical trials suggests that a new understanding of monocyte/macrophage infiltration may be necessary. Here we demonstrate that random migration, and not only chemotaxis, drives macrophage tumor infiltration. We identified tumor- associated monocytes (TAMos) that display a dramatically enhanced migration capability, induced rapidly by the tumor microenvironment, that drives effective tumor infiltration, in contrast to low-motility differentiated macrophages. TAMo, not TAMΦ, promotes cancer cell proliferation through activation of the MAPK pathway. IL-6 secreted both by cancer cells and TAMo themselves enhances TAMo migration by increasing dendritic protrusion dynamics and myosin- based contractility via the JAK2/STAT3 signaling pathway. Independent from CCL2 mediated chemotaxis, IL-6 driven enhanced migration and pro-proliferative effect of TAMo were validated in a syngeneic TNBC mouse model. Depletion of IL-6 in cancer cells significantly attenuated monocyte infiltration and reversed TAMo-induced cancer cell proliferation. This work reveals the critical role random migration plays in monocyte driven TAMΦ enrichment in a tumor and pinpoints IL-6 as a potential therapeutic target in combination with CCL2 to ameliorate current strategies against TAMΦ infiltration.

Promoting biological similarity by collagen microfibers in 3D colorectal cancer-stromal tissue: Replicating mechanical properties and cancer stem cell markers

The extracellular matrix (ECM) of cancer tissues is rich in dense collagen, contributing to the stiffening of these tissues. Increased stiffness has been reported to promote cancer cell proliferation, invasion, metastasis, and prevent drug delivery. Replicating the structure and mechanical properties of cancer tissue in vitro is essential for developing cancer treatment drugs that target these properties. In this study, we recreated specific characteristics of cancer tissue, such as collagen density and high elastic modulus, using a colorectal cancer cell line as a model. Using our original material, collagen microfibers (CMFs), and a constructed three-dimensional (3D) cancer-stromal tissue model, we successfully reproduced an ECM highly similar to in vivo conditions. Furthermore, our research demonstrated that cancer stem cell markers expressed in the 3D cancer-stromal tissue model more closely mimic in vivo conditions than traditional two-dimensional cell cultures. We also found that CMFs might affect an impact on how cancer cells express these markers. Our 3D CMF-based model holds promise for enhancing our understanding of colorectal cancer and advancing therapeutic approaches. Statement of significanceReproducing the collagen content and stiffness of cancer tissue is crucial in comprehending the properties of cancer and advancing anticancer drug development. Nonetheless, the use of collagen as a scaffold material has posed challenges due to its poor solubility, hindering the replication of a cancer microenvironment. In this study, we have successfully recreated cancer tissue-specific characteristics such as collagen density, stiffness, and the expression of cancer stem cell markers in three-dimensional (3D) colorectal cancer stromal tissue, utilizing a proprietary material known as collagen microfiber (CMF). CMF proves to be an ideal scaffold material for replicating cancer stromal tissue, and these 3D tissues constructed with CMFs hold promise in contributing to our understanding of cancer and the development of therapeutic drugs.