Facilitate Tumor Growth Research Articles

Involvement of Ataxin-3 (ATXN3) in the malignant progression of pancreatic cancer via deubiquitinating HDAC6

BackgroundPancreatic cancer is a common digestive system cancer and one of the most lethal malignancies worldwide. Ataxin-3 (ATXN3) protein is a deubiquitinating enzyme implicated in the occurrence of diverse human cancers. The potential role of ATXN3 in pancreatic cancer still remains unclear. MethodsATXN3 was screened from differentially-upregulated genes of GSE71989, GSE27890 and GSE40098 datasets. The mRNA and protein levels of ATXN3 was evaluated in pancreatic cancer samples and cell lines. Through the gain- and loss-of-function experiments, the effects of ATXN3 on cell proliferation, migration and invasion were evaluated using cell counting kit-8 (CCK-8), 5-ethynyl-2′-deoxyuridine (EdU) staining, wound healing and Transwell assays. Subsequently, the interaction between ATXN3 and HDAC6 was confirmed using double immunofluorescence staining, co-immunoprecipitation (co-IP) and proximity ligation assay (PLA). The underlying mechanism of ATXN3 was determined by knockdown of HDAC6 in ATXN3-upregulated pancreatic cancer cells. The function of ATXN3 in vivo was verified through xenograft assay. ResultsHigh expression of ATXN3 was found in pancreatic cancer tissues. Increased ATXN3 expression dramatically promoted cell proliferation, migration, and invasion. The malignant phenotypes were suppressed in ATXN3-silenced pancreatic cancer cells. ATXN3 was proved to interact with HDAC6 and regulate its degradation through deubiquitination. Downregulation of HDAC6 inhibited ATXN3-induced development of pancreatic cancer cells through regulating the expression of PCNA, vimentin and E-cadherin. ATXN3 facilitated tumor growth of pancreatic cancer and increased HDAC6 expression in vivo. ConclusionsThis study confirmed that ATXN3 facilitated malignant phenotypes of pancreatic cancer via reducing the ubiquitination of HDAC6.

LncRNA HOTTIP facilitated tumor growth via stimulating the hnRNPA2B1/DKK1/Wnt/β-catenin regulatory axis in hepatocellular carcinoma

LncRNA HOTTIP facilitated tumor growth via stimulating the hnRNPA2B1/DKK1/Wnt/β-catenin regulatory axis in hepatocellular carcinoma

TRIM28 promotes the escape of gastric cancer cells from immune surveillance by increasing PD-L1 abundance

Immune checkpoint blockade (ICB) offers a new opportunity for treatment for gastric cancer (G.C.). Understanding the upstream regulation of immune checkpoints is crucial to further improve the efficacy of ICB therapy. Herein, using the CRISPR-Cas9-based genome-wide screening, we identified TRIM28 as one of the most significant regulators of PD-L1, a checkpoint protein, in G.C. cells. Mechanistically, TRIM28 directly binds to and stabilizes PD-L1 by inhibiting PD-L1 ubiquitination and promoting PD-L1 SUMOylation. Furthermore, TRIM28 facilitates K63 polyubiquitination of TBK1, activating TBK1-IRF1 and TBK1-mTOR pathways, resulting in enhanced PD-L1 transcription. It was found that TRIM28 was positively correlated with PD-L1 in G.C. cells. Moreover, high TRIM28 expression suggests poor survival in a cohort of 466 patients with G.C., and this observation is consistent while analyzing data from publicly available databases. Ectopic TRIM28 expression facilitated tumor growth, increased PD-L1 expression, and suppressed T cell activation in mice. Administration of the PD-L1 or TBK1 inhibitor significantly alleviated the TRIM28-induced tumor progression. Furthermore, combining the TBK1 inhibitor with CTLA4 immune checkpoint blockade has synergistic effects on G.C., and provides a novel strategy for G.C. therapy.

CXCR2 expression during melanoma tumorigenesis controls transcriptional programs that facilitate tumor growth

BackgroundThough the CXCR2 chemokine receptor is known to play a key role in cancer growth and response to therapy, a direct link between expression of CXCR2 in tumor progenitor cells during induction of tumorigenesis has not been established.MethodsTo characterize the role of CXCR2 during melanoma tumorigenesis, we generated tamoxifen-inducible tyrosinase-promoter driven BrafV600E/Pten−/−/Cxcr2−/− and NRasQ61R/INK4a−/−/Cxcr2−/− melanoma models. In addition, the effects of a CXCR1/CXCR2 antagonist, SX-682, on melanoma tumorigenesis were evaluated in BrafV600E/Pten−/− and NRasQ61R/INK4a−/− mice and in melanoma cell lines. Potential mechanisms by which Cxcr2 affects melanoma tumorigenesis in these murine models were explored using RNAseq, mMCP-counter, ChIPseq, and qRT-PCR; flow cytometry, and reverse phosphoprotein analysis (RPPA).ResultsGenetic loss of Cxcr2 or pharmacological inhibition of CXCR1/CXCR2 during melanoma tumor induction resulted in key changes in gene expression that reduced tumor incidence/growth and increased anti-tumor immunity. Interestingly, after Cxcr2 ablation, Tfcp2l1, a key tumor suppressive transcription factor, was the only gene significantly induced with a log2 fold-change greater than 2 in these three different melanoma models.ConclusionsHere, we provide novel mechanistic insight revealing how loss of Cxcr2 expression/activity in melanoma tumor progenitor cells results in reduced tumor burden and creation of an anti-tumor immune microenvironment. This mechanism entails an increase in expression of the tumor suppressive transcription factor, Tfcp2l1, along with alteration in the expression of genes involved in growth regulation, tumor suppression, stemness, differentiation, and immune modulation. These gene expression changes are coincident with reduction in the activation of key growth regulatory pathways, including AKT and mTOR.

Prognostic values of circulating TREM2+ and ARG1+ Mreg cells in adults with treatment‐naïve diffuse large B‐cell lymphoma

Introduction: Novel Trem2+ (triggering receptor expressed on myeloid cells 2) and Arg1+ (arginase 1) regulatory myeloid cells (Mreg) that lead to the dysfunction of CD8+ T cells and facilitate tumor growth were recently discovered in a murine cancer model by Yonatan Katzenelenbogen et al. However, as the roles of Mreg cells have never been examined in human cancer patients, we aim to elucidate the clinical impact of circulating Mreg cells on patients with treatment-naive B-cell NHL, especially focusing on DLBCL. Methods: This prospective, observational study enrolled 102 adults with newly diagnosed and treatment-naïve B-cell NHL, including 62 DLBCL, 25 FL (4 grade 3B), 4 MCL, 4 MZL, 2 LPL, 2 BL, and 3 mature B-cell neoplasms, from December 2020 to November 2022. We obtained human circulating TREM2+ and ARG1+ Mreg cells from freshly isolated peripheral blood and calculated their percentages among CD45+ and CD15- cells by flow-cytometry analysis. Non-stain (NS) and fluorescence minus one (FMO) controls were used for gating positive levels of surface TREM2 and intracellular ARG1, respectively. Results: Among 102 patients with B-cell NHL, those with high-risk IPI had significantly higher percentages of circulating Mreg cells than patients with intermediate or low-risk IPI (5.46% vs. 1.71% vs. 0.63%, P H vs. L < 0.001, P H vs. I = 0.032, P I vs. L = 0.005); patients with aggressive subtypes (including grade-3B FL) had significantly higher percentages of circulating Mreg cells than patients with indolent subtypes (1.89% vs. 0.93%, P = 0.023). For 62 DLBCL patients, those with high IPI risk (9.18% vs. 1.25%, P < 0.001), bulky mass ≥ 7.5 cm (5.08% vs. 1.18%, P = 0.057), or DEL (5.13% vs. 1.21%, P = 0.036) had significantly higher percentages of circulating Mreg cells (Figures A–F). More importantly, DLBCL patients with circulating Mreg cells ≥4.5% had significantly worse PFS and OS than those with Mreg cells <4.5% after a median follow-up of 14 months (Figures G and H); when utilizing multivariate Cox regression analysis, “circulating Mreg cells ≥4.5%” remained an independent prognostic factor for both PFS and OS after adjusting for confounding factors, including age, sex, high-risk IPI, bulky mass ≥7.5 cm, BM involvement, non-GCB type, and DEL. The research was funded by: The research was funded by grants from: (1) the Taiwan Ministry of Science and Technology (MOST 111-2314-B-075-037), (2) Taipei Veterans General Hospital (V110B-012), (3) the Chong Hin Loon Memorial Cancer and Biotherapy Research Center, (4) the Melissa Lee Cancer Foundation, and (5) the Taiwan Clinical Oncology Research Foundation. Keywords: Aggressive B-cell non-Hodgkin lymphoma, Diagnostic and Prognostic Biomarkers No conflicts of interests pertinent to the abstract.

EXPLORING THE POTENTIAL CORRELATION BETWEEN NEUTROPHIL EXTRACELLULAR TRAPS AND PROGNOSIS IN PATIENTS WITH DIFFUSE LARGE B‐CELL LYMPHOMA AND HODGKIN’S LYMPHOMA

Introduction: Neutrophil extracellular traps (NETs) are web-like structures of decondensed chromatin and granule proteins that are released from neutrophils in response to infection. NET-release also occurs and contributes to inflammation, organ dysfunction and thrombosis in patients with non-infectious inflammatory conditions, such as cancer. In several solid cancer types, NETs have been associated with poorer prognosis by facilitating tumour growth and metastasis. One study has associated NETs with tumour progression and poorer prognosis in diffuse large B-cell lymphoma (DLBCL), however the knowledge of the role of NETs in lymphoma is sparse. Here, NETs were measured in plasma from patients with DLBCL and Hodgkin’s lymphoma (HL), and correlated to blood counts and clinical outcome of the patients. Methods: Plasma samples from patients with DLBCL (n = 72) and HL (n = 54), diagnosed between 2010 and 2015, were obtained from the Swedish Uppsala Umeå Comprehensive Cancer Consortium (U-CAN) biobank. The lymphoma samples, as well as healthy controls (n = 11), were analysed using a commercial enzyme-linked immunosorbent assay (ELISA) targeting citrullinated histone 3 in complex with externalized DNA, a biomarker considered specific for NETs. Data collected from patient records, including routine blood counts at diagnosis, clinical background and disease outcome, was correlated to the obtained plasma concentrations of NETs. Results: DLBCL and HL patients showed significantly elevated concentrations of NETs in plasma compared to healthy controls (median concentrations 60.07, 65.24 and 5.366 ng/mL, p < 0.0001). In both DLBCL and HL, trends towards better overall survival (p = 0.3308 and 0.0534 respectively) and better progression free survival (p = 0.2777 and 0.1056) were seen for patients with concentrations of NETs above median. While there was no correlation between sex or age and NET levels in DLBCL patients, HL patients under the age of 50 years showed a significant correlation with higher levels of NETs (p = 0.0021). In both DLBCL and HL patients, plasma NET-levels showed a positive correlation with the neutrophil count in blood at diagnosis (p = 0.0087 and 0.0001 respectively). A neutrophil-lymphocyte ratio above 3.0, a known predictor of worse outcome in cancer patients, showed a trend towards being correlated with worse prognosis in DLBCL patients, but this was less evident for HL patients. Keywords: aggressive B-cell non-Hodgkin lymphoma, diagnostic and prognostic biomarkers, Hodgkin lymphoma No conflicts of interests pertinent to the abstract.

MiR-143-3p shuttled by M2 macrophage-derived extracellular vesicles induces progression of colorectal cancer through a ZC3H12A/C/EBPβ axis-dependent mechanism.

Extracellular vesicles (EVs) exhibit pivotal functions in cancer via intercellular communication through shuttling microRNA (miRNA) and protein. Therefore, we aim to elucidate the function of EVs containing miR-143-3p derived from M2 macrophages in colorectal cancer (CRC). EVs derived from M2 macrophages were isolated and characterized. Expression changes in miR-143-3p were calculated in the EVs. The effects of M2 macrophage-derived EV carrying miR-143-3p on cell biological processes and in vivo tumorigenic ability concerning ZC3H12A were examined. EVs derived from M2 macrophages could stimulate the aggressive tumor biology of CRC cells. Meanwhile, in vivo results showed that M2 macrophage-derived EVs facilitated tumor growth and epithelial-mesenchymal transition. M2 macrophage-secreted EVs could transfer miR-143-3p to CRC cells, in which miR-143-3p bound to the 3'UTR of ZC3H12A and inhibited its expression, leading to elevation of the expression of transcription factor C/EBPβ. Overall, M2 macrophage-derived EV miR-143-3p inhibits ZC3H12A gene and increases C/EBPβ expression to facilitate the development of CRC, which provides novel targets for the molecular treatment of CRC.

Fusobacterium nucleatum-derived small extracellular vesicles facilitate tumor growth and metastasis via TLR4 in breast cancer

BackgroundThe contributive role of the microbiome in tumor progression has been reported in multiple studies, such as the Fusobacterium nucleatum (F. nucleatum) in breast cancer (BC). This study aimed to explore the role of F. nucleatum-derived small extracellular vesicles (Fn-EVs) in BC and preliminarily uncover the mechanism.MethodsTen normal and 20 cancerous breast tissues were harvested to investigate the gDNA expression of F. nucleatum and its relation with the clinical characteristics of BC patients. After isolating Fn-EVs by ultracentrifugation from F. nucleatum (ATCC 25,586), both MDA-MB-231 and MCF-7 cells were treated with PBS, Fn, or Fn-EVs, followed by being subjected to CCK-8, Edu staining, wound healing, and Transwell assays to detect their cell viability, proliferation, migration, and invasion. TLR4 expression in BC cells with diverse treatments was assessed by western blot. In vivo experiments were performed to verify its role in tumor growth and liver metastasis.ResultsThe F. nucleatum gDNA levels of breast tissues in BC patients were significantly higher than those in normal subjects, and positively associated with tumor size and metastasis. Fn-EVs administration significantly enhanced the cell viability, proliferation, migration, and invasion of BC cells, while knocking down TLR4 in BC cells could block these effects. Furthermore, in vivo study verified the contributive role of Fn-EVs in tumor growth and metastasis of BC, which might rely on its regulation of TLR4.ConclusionsCollectively, our results suggest that F. nucleatum plays an important role in BC tumor growth and metastasis by regulating TLR4 through Fn-EVs. Thus, a better understanding of this process may aid in the development of novel therapeutic agents.

Endothelial Cell-Selective Adhesion Molecule Enhances Tumor Growth in a HFpEF Mouse Model

Accumulating epidemiological evidence shows that the incidence of multiple types of cancer, such as melanoma and GI cancers, is significantly higher in patients with heart failure with preserved ejection fraction (HFpEF). However, the mechanistic relationships between HFpEF and cancer development are poorly understood. Impaired angiogenesis, upregulation of endothelial adhesion molecules and chronic low-grade inflammation are common in HFpEF. Here we examined the role of endothelial cell-selective adhesion molecule (ESAM) in the progression of malignant melanoma in a HFpEF mouse model. Orthotopic melanoma xenografts (B16F10-Luc2) were used and implanted subcutaneously in mice underwent uninephrectomy and aldosterone infusion (UNX-Aldo with 1% high salt drinking water for 4 weeks) and tumor growth was monitored with bioluminescent imaging. We found that ESAM expression and serum levels were elevated in the UNX-Aldo mice, which was accompanied by enhanced melanoma growth and metastasis rate. ESAM promoted tube formation and increased phospho-Akt, phospho-PKCα and phospho-ERK1/2 in cultured endothelial cells. Flow cytometry analysis showed elevated number of tumor-associated neutrophils (CD11b+Ly6G+Ly6C-) and myeloid-derived suppressor cells (MDSCs, CD11b+F4/80-Gr-1+) in the UNX-Aldo mice. UNX-Aldo mice with genetic deletion of ESAM (ESAM KO) showed a reduced tumor growth and reduced number of tumor-associated neutrophils and MDSCs. Collectively, our results indicate that in HFpEF, a proinflammatory ESAM activation may act to promote tumor angiogenesis, neutrophil and MDSCs tumor infiltration, thereby mitigating a proper immune response and facilitate tumor growth. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Targeting Oncometabolites in Peritoneal Cancers: Preclinical Insights and Therapeutic Strategies.

Peritoneal cancers present significant clinical challenges with poor prognosis. Understanding the role of cancer cell metabolism and cancer-promoting metabolites in peritoneal cancers can provide new insights into the mechanisms that drive tumor progression and can identify novel therapeutic targets and biomarkers for early detection, prognosis, and treatment response. Cancer cells dynamically reprogram their metabolism to facilitate tumor growth and overcome metabolic stress, with cancer-promoting metabolites such as kynurenines, lactate, and sphingosine-1-phosphate promoting cell proliferation, angiogenesis, and immune evasion. Targeting cancer-promoting metabolites could also lead to the development of effective combinatorial and adjuvant therapies involving metabolic inhibitors for the treatment of peritoneal cancers. With the observed metabolomic heterogeneity in cancer patients, defining peritoneal cancer metabolome and cancer-promoting metabolites holds great promise for improving outcomes for patients with peritoneal tumors and advancing the field of precision cancer medicine. This review provides an overview of the metabolic signatures of peritoneal cancer cells, explores the role of cancer-promoting metabolites as potential therapeutic targets, and discusses the implications for advancing precision cancer medicine in peritoneal cancers.

Tumor-associated NK cells facilitate tumor growth via NKp46 in immunocompetent murine hepatocellular carcinoma

Natural killer(NK) cells comprise one subset of the innate lymphoid cells family. Despite reported anti-tumor activity of NK cells, their tangible contribution to tumor control remains controversial. This is due to the incomplete understanding of NK alterations within tumor microenvironment(TME). Here we showed, using murine hepatocellular carcinoma(HCC) model, that early NK cells deletion markedly attenuated tumor growth in a CD8+T cells dependent manner. This effect was accompanied by an enhanced CD8+T cells effector function in tumor rather than circulating blood. Then, we demonstrated that abundant NKp46+ NK subset, but not NKp46− NK, were recruited towards tumor microenvironment during tumor progression. Frequency of intratumor NKP46+ NK cells were inversely related to CD8+T cells activation, and positively correlated with tumor growth. Intratumor NKp46+ NK cells exhibited dysfunction and increased expression of inhibitory receptors, when compared with NKp46− NK cells. Blockade of NK cells-associated NKp46 effectively attenuated HCC growth. Infusion of tumor-derived NKp46+ NK cells markedly enhanced HCC growth in vivo, in contrast to tumor cells inoculation alone. The further mechanistic investigations unveiled that NK cells boosted tumor growth by NKp46-mediated impairment of CD8+T cells effector function.Overall, this work supported a previously unappreciated regulatory property of tumor-associated NK cells in HCC, and NKp46 as a potential target against HCC in clinical setting.

Aberrant expression of circular RNA DHPR facilitates tumor growth and metastasis by regulating the RASGEF1B/RAS/MAPK axis in hepatocellular carcinoma.

Circular RNAs (circRNAs) are noncoding RNAs. Accumulating evidence suggests that circRNAs play a critical role in human biological processes, especially tumorigenesis, and development. However, the exact mechanisms of action of circRNAs in hepatocellular carcinoma (HCC) remain unclear. Bioinformatic tools and RT-qPCR were used to identify the role of circDHPR, a circRNA derived from the dihydropteridine reductase (DHPR) locus, in HCC and para-carcinoma tissues. Kaplan-Meier analysis and the Cox proportional hazard model were used to analyze the correlation between circDHPR expression and patient prognosis. Lentiviral vectors were used to establish stable circDHPR-overexpressing cells. In vitro and in vivo studies have shown that tumor proliferation and metastasis are affected by circDHPR. Mechanistic assays, including Western blotting, immunohistochemistry, dual-luciferase reporter assays, fluorescence in situ hybridization, and RNA immunoprecipitation, have demonstrated the molecular mechanism underlying circDHPR. CircDHPR was downregulated in HCC, and low circDHPR expression was associated with poor overall survival and disease-free survival rates. CircDHPR overexpression inhibits tumor growth and metastasis in vitro and in vivo. Further systematic studies revealed that circDHPR binds to miR-3194-5p, an upstream regulator of RASGEF1B. This endogenous competition suppresses the silencing effect of miR-3194-5p. We confirmed that circDHPR overexpression inhibited HCC growth and metastasis by sponging miR-3194-5p to upregulate the expression of RASGEF1B, which is regarded as a suppressor of the Ras/MAPK signaling pathway. Aberrant circDHPR expression leads to uncontrolled cell proliferation, tumorigenesis, and metastasis. CircDHPR may serve as a biomarker and therapeutic target for HCC.

CircABCA13 acts as a miR-4429 sponge to facilitate esophageal squamous cell carcinoma development by stabilizing SRXN1.

Circular RNAs (circRNAs) play a pivotal role in the tumorigenesis and progression of various cancers. However, the role and mechanisms of circABCA13 in esophageal squamous cell carcinoma (ESCC) are largely unknown. Here, we reported that circABCA13, a novel circular RNA generated by back-splicing of the intron of the ABCA13 gene, is highly expressed in ESCC tumor tissues and cell lines. Upregulation of circABCA13 correlated with TNM stage and a poor prognosis in ESCC patients. While knockdown of circABCA13 in ESCC cells significantly reduced cell proliferation, migration, invasion, and anchorage-independent growth, overexpression of circABCA13 facilitated tumor growth both in vitro and in vivo. In addition, circABCA13 directly binds to miR-4429 and sequesters miR-4429 from its endogenous target, SRXN1 mRNA, which subsequently upregulates SRXN1 and promotes ESCC progression. Consistently, overexpression of miR-4429 or knockdown of SRXN1 abolished malignant behavior promotion of ESCC results from circABCA13 overexpression in vitro and in vivo. Collectively, our study uncovered the oncogenic role of circABCA13 and its mechanism in ESCC, suggesting that circABCA13 could be a potential therapeutic target and a predictive biomarker for ESCC patients.

Abstract 3528: ALKBH5 promotes cancer growth by regulating ER homeostasis via UPR, autophagy, and mitochondrial function

Abstract Background: N6-methyladenosine (m6A) RNA methylation is a dynamic reversible epitranscriptomic modification that includes methyl transferases (writes m6A), demethylases (erases m6A) and reader proteins, which proofreads m6A marks of a specific site of transcripts. Recent studies have suggested that RNA methylation affects several fundamental cellular and molecular functions including mRNA splicing, stability, export, stem cell fate, circadian rhythms, DNA repair and cell survival. The objective of this study is to establish the mechanisms by which RNA demethylase ALKBH5 (AlkB homolog 5) facilitates tumor growth and progression. Methods: To establish the significance of RNA methylation in children’s cancers, we performed siRNA screen targeting m6A writers, erasers, and readers in osteosarcoma (OS). We used several OS cell lines including 143B, MG63, SaOS2, U2OS and multiple patient derived OS cell lines. Mechanistic studies were conducted using ALKBH5 KO and knockdown cells and by measuring the status of Autophagy and UPR associated proteins using Western blot analysis, confocal and electron microscopy. Results: Our results revealed that depletion of ALKBH5, a demethylase that erases the m6A mark from the target gene, altered the autophagy in OS cells. Interestingly, we found that level of LC3, which is the universal marker for autophagy, was significantly increased in OS cells. RNA seq analysis showed that depletion of ALKBH5 significantly altered several autophagy related genes in the OS cells. To better understand the molecular mechanism by which ALKBH5 regulates autophagy, we investigated the Endoplasmic Reticulum (ER) stress-induced Unfolded Protein Response (UPR) pathway, which is a known activator of autophagy. We discovered that ER stress induced UPR signaling pathway is highly activated in ALKBH5 depleted cancer cells. Further, mechanistic studies suggested that ALKBH5 promoted ER homeostasis by controlling the expression of ER lipid raft associated 1 (ERLIN1), which binds to the activated inositol 1, 4, 5,-triphosphate receptor and facilitates its degradation via ERAD to maintain calcium flux between ER and mitochondria. Using functional studies and electron microscopy, we show that ALKBH5-ERLIN1-IP3R-dependent calcium signaling modulates the activity of AMP kinase, and consequently mitochondrial biogenesis. These findings thus reveal that ALKBH5 serves an important role in maintaining ER homeostasis and cellular fitness. Conclusion: These findings provide novel insight into how m6A may promote cancer cell growth by regulating the crosstalk among ER signaling, UPR, autophagy, and mitochondrial function. Our study is the first to show that RNA methylation plays an important role in osteosarcoma by regulating autophagy via UPR. Citation Format: Panneerdoss Subbarayalu, Daisy Medina, Pooja Yadav, Santosh Timilsina, Kunal Baxi, Ratna Vadlamudi, Yidong Chen, Manjeet Rao. ALKBH5 promotes cancer growth by regulating ER homeostasis via UPR, autophagy, and mitochondrial function. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3528.

C1orf109 promotes malignant phenotype of liver cancer via wnt signaling pathway in a CK2-dependent manner

Chromosome 1 open reading frame 109 (C1orf09) is a protein whose expression pattern and biological function in humans, particularly in malignant tumors, have not been explored. In this study, both bioinformatics and immunohistochemical staining revealed that C1orf109 was overexpressed in the cytoplasm of liver cancer cells, and the positive ratio of C1orf109 in liver cancer samples (42.5%, 37/87) was significantly higher than that in normal liver tissues (10%, 3/30, P = 0.0012). C1orf109 expression was correlated with an advanced TNM stage (P = 0.017) and vascular invasion (P = 0.023) and predicted the poor overall survival of patients with liver cancer (P = 0.001). C1orf109 facilitated tumor growth, colony formation, migration, and invasion by activating Wnt signaling by upregulating non-phosphorylated β-catenin and its downstream target genes such as CyclinD1, c-myc, and MMP7. Our results also suggest that C1orf109 interacts and co-localizes with casein kinase II (CK2) to activate Wnt signaling. Treatment with a CK2-specific inhibitor markedly counteracted the increased expression of CyclinD1, c-Myc, and MMP7, as well as the upregulation of tumor proliferation and invasion caused by C1orf109 overexpression. Taken together, our results indicate that C1orf109 accelerates liver cancer cell proliferation and invasion by strengthening the Wnt signaling pathway in a CK2-dependent manner.

Influencing Factors and Significance of Tumor-associated Macrophage Polarization in Tumor Microenvironment

Tumor-associated macrophages (TAMs), characterized by high plasticity, are the most abundant immune cells in the tumor microenvironment (TME). TAMs are recruited to tumor region in response to various TME components such as cytokines, chemokines as well as exosomes. Subsequently, these environmental cues induce a certain polarization state of TAMs, ranging from anti-tumor states (M1-like) to pro-tumor states (M2-like). Furthermore, the polarization process of TAMs is continuous and gradually inclines toward the M2-like state with malignant progression, forming a positive feedback loop that facilitates tumor growth and metastasis. Consequently, figuring out the factors and mechanisms affecting TAMs polarization is beneficial for developing novel therapeutic strategies that can be combined with other immunotherapies for lung cancer. In previous studies, many significant molecules and pathways which could promote the M2 polarization of TAMs were identified. However, the underlying mechanisms of this sophisticated cross-talk between tumor cells, stroma cells and TAMs remain still difficult to by fully understand. In this review, we summarize the comprehensive factors involved in triggering TAMs polarization towards the M2 phenotype and further explore the relevant molecular mechanisms. .

ANGPTL2 promotes VEGF-A synthesis in human lung cancer and facilitates lymphangiogenesis.

Lung cancer is an extremely common cancer and metastatic lung cancer has a greatly low survival rate. Lymphangiogenesis is essential for the development and metastasis of lung cancer. The adipokine angiopoietin-like protein 2 (ANGPTL2) regulates tumor progression and metastasis, although the functions of ANGPTL2 in lung cancer are unknown. Analysis of data from TCGA genomics program, the GEPIA web server and the Oncomine database revealed that higher levels of ANGPTL2 expression were correlated with progressive disease and lymph node metastasis. ANGPTL2 enhanced VEGF-A-dependent lymphatic endothelial cell (LEC) tube formation and migration. Integrin α5β1, p38 and nuclear factor (NF)-κB signaling mediated ANGPTL2-regulated lymphangiogenesis. Importantly, overexpression ANGPTL2 facilitated tumor growth and lymphangiogenesis in vivo. Thus, ANGPTL2 is a promising therapeutic object for treating lung cancer.

Repeated activation of Trpv1-positive sensory neurons facilitates tumor growth associated with changes in tumor-infiltrating immune cells.

It is considered that sensory neurons extend into the tumor microenvironment (TME), which could be associated with tumor growth. However, little is known about how sensory signaling could promote tumor progression. In this study, chemogenetic activation of transient receptor potential vanilloid 1 (Trpv1)-positive sensory neurons (C-fibers) by the microinjection of AAV-hSyn-FLEX-hM3Dq-mCherry into the sciatic nerve dramatically increased tumor volume in tumor-bearing Trpv1-Cre mice. This activation in Trpv1::hM3Dq mice that had undergone tumor transplantation significantly reduced the population of tumor-infiltrating CD4+ T cells and increased the mRNA level of the M2-macrophage marker, CX3C motif chemokine receptor 1 (Cx3cr1) in immunosuppressive cells, such as tumor-associated macrophages (TAMs) and tumor-infiltrating monocytic myeloid-derived suppressor cells (M-MDSCs). Under these conditions, we found a significant correlation between the decreased expression of the M1-macrophage marker Tnf and tumor volume. These findings suggest that repeated activation of Trpv1-positive sensory neurons may facilitate tumor growth along with changes in tumor-infiltrating immune cells.

KIF2C Facilitates Tumor Growth and Metastasis in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal cancer with a poor prognosis. For PDAC, an increase in the survival time of patients and a reduction mortality have not yet successfully been achieved. In many research works, Kinesin family member 2C (KIF2C) is highly expressed in several tumors. Nevertheless, the role of KIF2C in pancreatic cancer is unknown. In this study, we found that KIF2C expression is significantly upregulated in human PDAC tissues and cell lines such as ASPC-1 and MIA-PaCa2. Moreover, KIF2C upregulation is associated with a poor prognosis when combining the expression of KIF2C with clinical information. Through cell functional assays and the construction of animal models, we showed that KIF2C promotes PDAC cell proliferation, migration, invasion, and metastasis, both in vitro and in vivo. Finally, the results of sequencing showed that the overexpression of KIF2C causes a decrease in some proinflammatory factors and chemokines. The cell cycle detection indicated that the pancreatic cancer cells in the overexpressed group had abnormal proliferation in the G2 and S phases. These results revealed the potential of KIF2C as a therapeutic target for the treatment of PDAC.

Long Noncoding RNA PCGEM1 Facilitates Tumor Growth and Metastasis of Osteosarcoma by Sponging miR-433-3p and Targeting OMA1.

Osteosarcoma (OS) is regarded as one of the most common malignant bone tumors, mainly occurring in children and adolescents with high mortality. The dysregulation of lncRNAs is reported to regulate tumor development and be closely related to patient prognosis. Nevertheless, the role of long noncoding RNAs (lncRNAs) prostate-specific transcript 1 (PCGEM1) in OS remains uncharacterized. The current study aimed to explore the role of PCGEM1 in OS. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to examine the expression of PCGEM1 in OS cell lines. CCK-8, colony formation, Transwell, and western blotting analyses were applied to measure OS cell viability, proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) after PCGEM1 downregulation. Nuclear-cytoplasmic fractionation, RNA pulldown, RNA immunoprecipitation (RIP), luciferase reporter assays were performed to verify the relationship among PCGEM1, miR-433-3p. and OMA1 in OS. The xenograft tumor models were established to evaluate the effect of PCGEM1 on tumor growth of OS. In this study, we discovered that PCGEM1 knockdown inhibited cell proliferation, migration, invasion and EMT in OS (P < 0.05). Additionally, PCGEM1 directly bound to miR-433-3p (P < 0.01). OMA1 was confirmed to be a target gene of miR-433-3p (P < 0.05), positively regulated by PCGEM1 but negatively regulated by miR-433-3p. Rescue assays further verified that overexpression of OMA1 reversed the PCGEM1 knockdown-mediated inhibitory effect on the malignant phenotype in OS cells (P < 0.05). Moreover, knockdown of PCGEM1 inhibited tumor growth and metastasis in vivo (P < 0.05). Overall, PCGEM1 mediated tumor growth and metastasis of OS by sponging miR-433-3p and regulating OMA1, which might provide an innovative strategy for OS diagnosis or treatment.