Cell Tumor Progression Research Articles

LncRNA-42060 Regulates Tamoxifen Sensitivity and Tumor Development via Regulating the miR-204-5p/SOX4 Axis in Canine Mammary Gland Tumor Cells.

Tamoxifen is the drug of choice for endocrine therapy of breast cancer. Its clinical use is limited by the development of drug resistance. There is increasing evidence that long non-coding RNAs (lncRNAs) are associated with tumor drug resistance. Therefore, we established two TAM-resistant cell lines, CHMpTAM and CHMmTAM. The different expression levels of lncRNA and miRNA in CHMmTAM and CHMm were screened by RNA sequencing, and the lncRNA-miRNA interactions were analyzed. LncRNA ENSCAFG42060 (lnc-42060) was found to be significantly upregulated in drug-resistant cells and tumor tissues. Further functional validation revealed that the knockdown of lnc-42060 inhibited proliferation, migration, clone formation, restoration of TAM sensitivity, and reduction of stem cell formation in drug-resistant cells, whereas overexpression of lnc-4206 showed opposite results. Bioinformatics and dual-luciferase reporter gene assays confirmed that lnc-42060 could act as a sponge for miR-204-5p, further regulating SOX4 expression activity and thus influencing tumor cell progression. In conclusion, we screened lncRNAs and miRNAs associated with TAM resistance in canine mammary gland tumor cells for the first time. lnc-42060 served as a novel marker that may be used as an important biomarker for future diagnosis and treatment.

A Signaling View into the Inflammatory Tumor Microenvironment

The development of tumors requires an initiator event, usually exposure to DNA damaging agents that cause genetic alterations such as gene mutations or chromosomal abnormalities, leading to deregulated cell proliferation. Although the mere stochastic accumulation of further mutations may cause tumor progression, it is now clear that an inflammatory microenvironment has a major tumor-promoting influence on initiated cells, in particular when a chronic inflammatory reaction already existed before the initiated tumor cell was formed. Moreover, inflammatory cells become mobilized in response to signals emanating from tumor cells. In both cases, the microenvironment provides signals that initiated tumor cells perceive by membrane receptors and transduce via downstream kinase cascades to modulate multiple cellular processes and respond with changes in cell gene expression, metabolism, and morphology. Cytokines, chemokines, and growth factors are examples of major signals secreted by immune cells, fibroblast, and endothelial cells and mediate an intricate cell-cell crosstalk in an inflammatory microenvironment, which contributes to increased cancer cell survival, phenotypic plasticity and adaptation to surrounding tissue conditions. Eventually, consequent changes in extracellular matrix stiffness and architecture, coupled with additional genetic alterations, further fortify the malignant progression of tumor cells, priming them for invasion and metastasis. Here, we provide an overview of the current knowledge on the composition of the inflammatory tumor microenvironment, with an emphasis on the major signals and signal-transducing events mediating different aspects of stromal cell-tumor cell communication that ultimately lead to malignant progression.

Identification of Neuregulin 1 as Predictor Outcome in Intracranial Astrocytoma

BACKGROUND: Astrocytoma is the most common primary brain tumor. The combination of adhesion molecules, proteases, and cytokines that regulate their expression likely underlies tumor progression. The cytokine of neuregulin 1 (NRG1) has a role in progression and invasion of tumor cells by activating signal after binding its receptor. AIM: To identification NRG1 expression with characteristic of intracranial astrocytoma patient is the purpose of this study. METHODS: This study uses analytic method with retrospective study. It analyzed the association between NRG1 expressions in astrocytoma patients. The study included 32 samples which were admitted to Haji Adam Malik Hospital Medan from September 2016 to August 2018. RESULTS: There was no significant association between NRG1 expression with age (p = 0.853) and gender (p = 0.565) of astrocytoma patients, while there was a significant association between NRG1 expression with cell proliferation (p = 0.00), WHO grading of astrocytoma (p = 0.00), and outcomes (p = 0.023). According to this study, the most common results are strong NRG1 expression has many cells proliferation in 10 (31.1%) patients, strong NRG1 expression with Grade IV astrocytoma found in 7 (21.9%) patients, and moderate NRG1 expression in live patient found in 7 (21.9%) patient. CONCLUSION: There is significant association between NRG1 expression and cell proliferation, WHO grading of astrocytoma, and outcomes.

Enhanced triacylglycerol catabolism by carboxylesterase 1 promotes aggressive colorectal carcinoma.

The ability to adapt to low-nutrient microenvironments is essential for tumor cell survival and progression in solid cancers, such as colorectal carcinoma (CRC). Signaling by the NF-κB transcription factor pathway associates with advanced disease stages and shorter survival in patients with CRC. NF-κB has been shown to drive tumor-promoting inflammation, cancer cell survival, and intestinal epithelial cell (IEC) dedifferentiation in mouse models of CRC. However, whether NF-κB affects the metabolic adaptations that fuel aggressive disease in patients with CRC is unknown. Here, we identified carboxylesterase 1 (CES1) as an essential NF-κB-regulated lipase linking obesity-associated inflammation with fat metabolism and adaptation to energy stress in aggressive CRC. CES1 promoted CRC cell survival via cell-autonomous mechanisms that fuel fatty acid oxidation (FAO) and prevent the toxic build-up of triacylglycerols. We found that elevated CES1 expression correlated with worse outcomes in overweight patients with CRC. Accordingly, NF-κB drove CES1 expression in CRC consensus molecular subtype 4 (CMS4), which is associated with obesity, stemness, and inflammation. CES1 was also upregulated by gene amplifications of its transcriptional regulator HNF4A in CMS2 tumors, reinforcing its clinical relevance as a driver of CRC. This subtype-based distribution and unfavorable prognostic correlation distinguished CES1 from other intracellular triacylglycerol lipases and suggest CES1 could provide a route to treat aggressive CRC.

Abstract P-24: Microscopic Analyses of Liquid-Liquid Phase Separation Induced by Linker Histone H1.0

Background: Liquid-liquid phase separation (LLPS) that leads to the formation of temporary functional domains in cells plays an important role in the processes of chromatin condensation and gene regulation. Earlier, it was demonstrated that histone H1.4 can form LLPS droplets with DNA. In the present work, LLPS was studied for histone H1.0, which is mainly expressed in differentiated and non-dividing cells. H1.0 is involved in cancer development: its amount decreases with the progression of tumor cells to malignancy. Methods: LSM710 confocal microscope (Zeiss) equipped with the 40x/1.2W objective was used to image mixtures of H1.0 with Cy3/Cy5 labeled DNA or nucleosomes in fluorescent and transmitted-light channels at the excitation of 514 nm. The formation of condensates as a result of LLPS was confirmed by salt-jump and FRAP/FLIP experiments. Results: Condensates were not observed when the ratio of negative to positive charges (N/P) in the samples was >1. At N/P~0.7, optically homogeneous droplet-like condensates were found. The appearance of condensates, their size and shape depended on concentrations of H1.0 and DNA. LLPS condensates but not aggregates disappeared by salt-jump to 650 mM NaCl. FRAP/FLIP experiments revealed a moderate rate of fluorescence recovery (τ½22s) indicating moderate DNA mobility of the H1.0-mediated condensates. The appearance of condensates was also observed in the mixtures of H1.0, DNA and Cy3/Cy5-labeled nucleosomes. Nucleosomes were involved in the condensate formation and found to be 2-fold more mobile (τ½10 s) than DNA. Conclusion: LLPS-related properties of H1.0 were studied for DNA and nucleosomes in vitro. Comparison with H1.4 shows that H1.0 forms liquid condensates of approximately the same size. Our result also may indicate that chromatin retains pronounced dynamic properties in H1.0-induced droplets despite the fact that H1.0 induces the formation of more compact chromatin.

Tumor Immune Microenvironment and Its Related miRNAs in Tumor Progression.

MiRNA is a type of small non-coding RNA, by regulating downstream gene expression that affects the progression of multiple diseases, especially cancer. MiRNA can participate in the biological processes of tumor, including proliferation, invasion and escape, and exhibit tumor enhancement or inhibition. The tumor immune microenvironment contains numerous immune cells. These cells include lymphocytes with tumor suppressor effects such as CD8+ T cells and natural killer cells, as well as some tumor-promoting cells with immunosuppressive functions, such as regulatory T cells and myeloid-derived suppressor cells. MiRNA can affect the tumor immune microenvironment by regulating the function of immune cells, which in turn modulates the progression of tumor cells. Investigating the role of miRNA in regulating the tumor immune microenvironment will help elucidate the specific mechanisms of interaction between immune cells and tumor cells, and may facilitate the use of miRNA as a predictor of immune disorders in tumor progression. This review summarizes the multifarious roles of miRNA in tumor progression through regulation of the tumor immune microenvironment, and provides guidance for the development of miRNA drugs to treat tumors and for the use of miRNA as an auxiliary means in tumor immunotherapy.

Infrared spectroscopic imaging study of BV-2 microglia altering tumor cell biological activity and cellular fraction

Tumor brain metastasis is a severe threat to patients’ neurological function, in which microglia may be involved in the process of tumor cell metastasis among nerve cells. Our study focused on the interaction between microglia and breast and lung cancer cells. Changes in the proliferation and migration ability of cocultured tumor cells were examined; synchrotron radiation-based fourier transform infrared microspectroscopy (SR-FTIR) was used to detect changes in the structures and contents of biomolecules within the tumor cells. The experimental results showed that the proliferation and migration ability of tumor cells increased after coculture, and the structures and contents of biological macromolecules in tumor cells changed. The absorption peak positions of the amide Ⅱ and amide Ⅰ bands observed for the four kinds of tumor cells changed, and the absorption intensities were significantly enhanced, indicating changes in the secondary structures and contents of proteins in tumor cells, which may be the root cause of the change in tumor cell characteristics. Therefore, the metabolites of microglia may be involved in the progression of tumor cells in the nervous system. In this study, we focused on the interaction between microglia and tumor cells by using SR-FTIR and provided a new understanding of the mechanism of brain metastasis.

Methanolic Extract from Sea Cucumber, Holothuria scabra, Induces Apoptosis and Suppresses Metastasis of PC3 Prostate Cancer Cells Modulated by MAPK Signaling Pathway.

Sea cucumber, Holothuria scabra, is a well-known traditional Asian medicine that has been used for suppressing inflammation, promoting wound healing, and improving immunity. Moreover, previous studies demonstrated that the extract from H. scabra contains many bioactive compounds with potent inhibitory effect on tumor cell survival and progression. However, the effect of the methanolic extract from the body wall of H. scabra (BWMT) on human prostate cancer cells has not yet been investigated. In this study, we aimed to investigate the effects and underlying mechanism of BWMT on prostate cancer cell viability and metastasis. BWMT was obtained by maceration with methanol. The effect of BWMT on cell viability was assessed by MTT and colony formation assays. The intracellular ROS accumulation was evaluated using a DCFH-DA fluorescence probe. Hoechst 33342 staining and Annexin V-FITC/PI staining were used to examine the apoptotic-inducing effect of the extract. A transwell migration assay was performed to determine the anti-metastasis effect. BWMT significantly reduced cell viability and triggered cellular apoptosis by accumulating intracellular ROS resulting in the upregulation of JNK and p38 signaling pathways. In addition, BWMT also inhibited the invasion of PC3 cells by downregulating MMP-2/-9 expression via the ERK pathway. Consequently, our study provides BWMT from H. scabra as a putative therapeutic agent that could be applicable against prostate cancer progression.

Reprogramming Immune Cells for Enhanced Cancer Immunotherapy: Targets and Strategies.

Cancer is one of the leading causes of death and a major public health problem all over the world. Immunotherapy is becoming a revolutionary clinical management for various cancer types. Restoration of aberrant immune surveillance on cancers has achieved markable progress in the past years by either in vivo or ex vivo engineering of the immune cells. Here, we summarized the central roles of immune cells in tumor progression and regression, and the existing and emerging strategies for different immune cell-based immunotherapies. In addition, the current challenges and the potential solutions in translating the immunotherapies into the clinic are also discussed.

Diagnostic value of syndecan-4 protein expression in colorectal cancer

The prognosis of patients with colorectal cancer (CRC) is highly dependent on the disease stage at diagnosis. Therefore, it is crucial to study molecules involved in the progression of colorectal cancer tumorigenesis and to shed light on their potential use as targetable proteins in diagnostics and therapy. As syndecan-4 (SDC4) is a transmembrane proteoglycan with important functions in cell adhesion, migration, cytoskeleton organization, and gene expression through the binding of extracellular matrix molecules, it might play a role in local tumor cell invasion.To clarify its impact on the progression of CRC, we analyzed 177 patients for SDC4 expression in colon carcinoma tissue, lymph node and liver metastasis under consideration of specific morphological features and cellular elements of CRC.Highly upregulated SDC4 was particularly expressed at the tumor invasion front. Expression was strongest in tumor cell buds appearing as membranous expression polarized to peritumoral stromal cells. Increased SDC4 expression directed to the tumor-stromal- or tumor-endothelial-interface was also confirmed for metastasis and angioinvasive tumor cell clusters. Furthermore, strong immunoreactivity of SDC4 in fibroblasts and macrophages being in contact with invasive tumor cells suggests a cooperation between the different types of cells in tumor progression at the cell-matrix interface and a role for SDC4 in tumor cells attached to the extracellular matrix.Overexpression of SDC4 in tumor cells at the invasion front was significantly associated with progressive pathological features and inversely related to disease-free and overall survival. Therefore, overexpression of SDC4 may be a predictor for poor prognosis in patients with CRC and might prove useful in clinical practice, thus identifying patients with potential disease progression.Further investigations will have to reveal the functional role of SDC4 in tumor cell buds, fibroblasts and macrophages at the tumor stromal interface to confirm that SDC4 might also be a possible therapeutic target for the treatment of patients with advanced CRC.

Exosomal Non-coding RNAs-Mediated Crosstalk in the Tumor Microenvironment.

Exosomes are secreted by different types of cells in tumor microenvironment (TME) and participate in multiple biological processes of tumors. Non-coding RNAs (ncRNAs) enveloped in exosomes and released to the TME are shown to be involved in tumorigenesis and development, as well as act as important intracellular communication mediators. However, the understanding on the exact regulatory functions and substrates of exosomal RNA is still at an early stage. In this review, we provided an overview on recent studies on exosomes mediating the modulation of both tumor cells and immune cells, then summarized the exosomal ncRNAs [such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs)] secreted by tumor cells and stromal cells that exhibited potential capabilities to regulate tumor cell growth, progression, metastasis, drug resistance, and immune response. Our review may hopefully inspire a deeper understanding on the ncRNAs’ function as useful biomarkers for the diagnosis, prognosis, and as novel targets therapy for cancer.

A Link between Replicative Stress, Lamin Proteins, and Inflammation.

Double-stranded breaks (DSB), the most toxic DNA lesions, are either a consequence of cellular metabolism, programmed as in during V(D)J recombination, or induced by anti-tumoral therapies or accidental genotoxic exposure. One origin of DSB sources is replicative stress, a major source of genome instability, especially when the integrity of the replication forks is not properly guaranteed. To complete stalled replication, restarting the fork requires complex molecular mechanisms, such as protection, remodeling, and processing. Recently, a link has been made between DNA damage accumulation and inflammation. Indeed, defects in DNA repair or in replication can lead to the release of DNA fragments in the cytosol. The recognition of this self-DNA by DNA sensors leads to the production of inflammatory factors. This beneficial response activating an innate immune response and destruction of cells bearing DNA damage may be considered as a novel part of DNA damage response. However, upon accumulation of DNA damage, a chronic inflammatory cellular microenvironment may lead to inflammatory pathologies, aging, and progression of tumor cells. Progress in understanding the molecular mechanisms of DNA damage repair, replication stress, and cytosolic DNA production would allow to propose new therapeutical strategies against cancer or inflammatory diseases associated with aging. In this review, we describe the mechanisms involved in DSB repair, the replicative stress management, and its consequences. We also focus on new emerging links between key components of the nuclear envelope, the lamins, and DNA repair, management of replicative stress, and inflammation.

The Effects of Quercetin on the Gene Expression of Arginine Metabolism Key Enzymes in Human Embryonic Kidney 293 Cells

Background: Arginine metabolism is an important factor involved in tumorigenesis, progression, and survival of tumor cells. Besides, other metabolites produced in the arginine metabolism process, such as polyamines, nitric oxide, argininosuccinate, and agmatine, play key roles in different stages of tumor development. On the other hand, herbal metabolites are widely used to treat cancer. One of these herbal flavonoids is quercetin. Methods: In this study, according to MTT assay data, two concentrations of quercetin flavonoid were selected (57.5 and 115 µM) to treat human embryonic kidney 293 (HEK293) cells. Then RNA was extracted from the cells and used as a template for cDNA synthesis. Using real-time PCR, the expression of key enzymes involved in arginine metabolism was evaluated, including arginase 2 (Arg2), ornithine carbamoyl transferase (OTC), agmatinase (AGMAT), arginase 1 (Arg1), nitric oxide synthase 1 (nNOS), arginine decarboxylase (ADC), ornithine decarboxylase 1 (ODC), ornithine carbamoyl transferase (OCT), spermidine synthase (SRM), spermine synthase (SMS), argininosuccinate synthase 1 (ASS1), and argininosuccinate lyase (ASL). The Student t-test was used to analyze the data considering a P value of < 0.05 as the significance level. Results: Our results indicated significant changes in the expression of arginine metabolism enzymes after quercetin exposure, confirming a role for quercetin plant flavonoid in regulating arginine metabolism in HEK293 cells. Conclusions: Quercetin could alter the gene expression of the key enzymes involved in arginine metabolism. This was the first study investigating the effects of quercetin on arginine metabolism in HEK293 cells.

Regulator of calcineurin 1 gene isoform 4 in pancreatic ductal adenocarcinoma regulates the progression of tumor cells

Therapeutic strategies to treat pancreatic ductal adenocarcinoma (PDAC) remain unsatisfying and limited. Therefore, it is imperative to fully determine the mechanisms underlying PDAC progression. In the present study, we report a novel role of regulator of calcineurin 1, isoform 4 (RCAN1.4) in regulating PDAC progression. We demonstrated that RCAN1.4 expression was decreased significantly in PDAC tissues compared with that in para-cancerous tissues, and correlated with poor prognosis of patients with pancreatic cancer. In vitro, stable high expression of RCAN1.4 could suppress the metastasis and proliferation and angiogenesis of pancreatic tumor cells. In addition, interferon alpha inducible protein 27 (IFI27) was identified as having a functional role in RCAN1.4-mediated PDAC migration and invasion, while VEGFA play a vital role in RCAN1.4-mediated PDAC angiogenesis. Analysis of mice with subcutaneously/orthotopic implanted xenograft tumors and liver metastasis model confirmed that RCAN1.4 could modulate the growth, metastasis, and angiogenesis of tumors via IFI27/VEGFA in vivo. In conclusion, our results suggested that RCAN1.4 suppresses the growth, metastasis, and angiogenesis of PDAC, functioning partly via IFI27 and VEGFA. Importantly, our results provided possible diagnostic criteria and therapeutic targets for PDAC.

Development and validation of a collagen signature-based nomogram for preoperatively predicting lymph node metastasis and prognosis in colorectal cancer.

BackgroundCurrent preoperative evaluation approaches cannot provide adequate information for the prediction of lymph node (LN) metastasis in colorectal cancer (CRC). Collagen alterations in the tumor microenvironment affect the progression of tumor cells. To more accurately assess the LN status of CRC preoperatively, we developed and validated a collagen signature-based nomogram for predicting LN metastasis in CRC.MethodsIn total, 342 consecutive CRC patients were assigned to the training and validation cohorts. A total of 148 fully quantitative collagen features were extracted based on preoperative biopsies using multiphoton imaging, and the least absolute shrinkage and selection operator method was utilized to construct the collagen signature. A collagen signature-based nomogram was developed by multivariable logistic regression in the training cohort. Nomogram performance was evaluated for its discrimination, calibration, and clinical usefulness and then validated in the validation cohort. The prognostic values of the nomogram were also evaluated.ResultsA seven-feature-based collagen signature was built. We found that the collagen signature showed a significant association with LN metastasis in CRC. Additionally, a nomogram incorporating preoperative tumor differentiation, computed tomography-reported T stage and LN status, carcinoembryonic antigen level, carbohydrate antigen 19-9 level and collagen signature was developed. This nomogram had good discrimination and calibration, with AUROCs of 0.826 and 0.846 in the training and validation cohorts, respectively, and had a sensitivity of 86.5%, a specificity of 68.2%, an accuracy of 76.9%, a negative predictive value of 84.9%, and a positive predictive value of 71.2% for all patients. Compared to the clinicopathological model, which consisted of the clinicopathological risk factors for LN metastasis, the collagen signature-based nomogram demonstrated a significantly improved ability to discriminate LN status. Moreover, a nomogram-predicted high-risk subgroup had remarkably reduced survival compared with that of the low-risk subgroup.ConclusionsThe collagen signature in the tumor microenvironment of preoperative biopsies is an independent predictor for LN metastasis in CRC, and the collagen signature-based nomogram is helpful for tailored treatment and prognostic predictions in CRC preoperatively.

Upregulation of SKA3 enhances cell proliferation and correlates with poor prognosis in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most aggressive types of malignancy worldwide. However, the mechanism underlying its frequent recurrence remains unclear. Studies have demonstrated that spindle and kinetochore associated complex subunit3(SKA3) is highly expressed in colorectal and prostate cancer. The present study aimed to determine whether SKA3 could be a predictive and prognostic marker for liver cancer. SKA3 expression levels inliver cancer cell lines, liver cancer tissues, normal liver cells and non‑cancerous tissues were compared at both transcriptional and translational levels. Correlation between SKA3 levels, clinicopathological characteristics and patient survival was also assessed. Gene set enrichment analysis(GSEA) was performed to identify SKA3‑associated pathways. Furthermore, SKA3 was knocked down and overexpressed in liver cancer cells, and then assessed the effect on cell proliferation, cell cycle, and tumor formation ability. Kaplan‑Meier survival analysis and log‑rank test were used to evaluate the association between SKA3 expression levels and prognosis. SKA3 mRNA and protein expression levels were significantly higher in liver cancer cell lines and clinical samples, compared with normal controls. Immunohistochemical analysis of 110patients revealed that upregulation of SKA3 correlated with clinical pathological characteristics and patient survival. GSEA showed that BENPORATH_PROLIFERATION gene set signaling pathways were correlated with SKA3 expression levels. Luciferase reporter activity assay revealed that knockdown of SKA3 significantly inhibited the activity of transcription factor E2F. Downregulation of SKA3 significantly inhibited cell proliferation, cell cycle arrest in G1‑Sphase and tumorigenesis both invitro and invivo, decreased the expression levels of cyclinD1 and phosphorylated‑-retinoblastoma and increased those of p21, suggesting a potential role of SKA3 in mediating tumor cell cycle and progression. SKA3 may function as an oncogene in liver cancer and may be a promising prognostic biomarker and candidate for targeted therapy.

Benzimidazole: A Multifacted Nucelus for Anticancer Agents

Cancer is characterized by an uncontrolled proliferation of cells, dedifferentiation, invasiveness and metastasis. Endothelial growth factor (eGF), insulin-like growth factor (IGF), platelet-derived growth factor (PDGF), Fibroblast growth factor (FGF), Vascular endothelial growth factor (VEGF), checkpoint kinase 1 & 2 ( Chk1 & Chk2), aurora kinases, topoisomerases, histone deacetylators (HDAC), poly(ADP-Ribose)polymerase (PARP), farnesyl transferases, RAS-MAPK pathway and PI3K-Akt-mTOR pathway, are some of the prominent mediators implicated in the proliferation of tumor cells. Huge artillery of natural and synthetic compounds as anticancer, which act by inhibiting one or more of the enzymes and/or pathways responsible for the progression of tumor cells, is reported in the literature. The major limitations of anticancer agents used in clinics as well as of those under development in literature are normal cell toxicity and other side effects due to lack of specificity. Hence, medicinal chemists across the globe have been working for decades to develop potent and safe anticancer agents from natural sources as well as from different classes of heterocycles. Benzimidazole is one of the most important and explored heteronucelus because of their versatility in biological actions as well as synthetic applications in medicinal chemistry. The structural similarity of amino derivatives of benzimidazole with purines makes it a fascinating nucleus for the development of anticancer, antimicrobial and anti-HIV agents. This review article is an attempt to critically analyze various reports on benzimidazole derivatives acting on different targets to act as anticancer so as to understand the structural requirements around benzimidazole nucleus for each target and enable medicinal chemists to promote rational development of antitumor agents.

Isochorismatase domain-containing protein 1 (ISOC1) participates in DNA damage repair and inflammation-related pathways to promote lung cancer development.

BackgroundThe advent of novel molecular targets has dramatically changed the treatment landscape of lung cancer in recent years. Isochorismatase domain-containing protein 1 (ISOC1) has been reported as a potential biomarker in gastrointestinal cancer, while its function in lung cancer has not been determined.MethodsThe expression levels and prognostic significance of ISOC1 were assessed using bioinformatic analysis. Overexpression of ISOC1 and miR-4633, and knockdown of ISOC1 in non-small cell lung cancer (NSCLC) cell lines were generated by lentiviral infection with overexpressed or shRNA plasmids. CRISPR/Cas9 system was applied to knockout ISOC1 in A549 cells. The functions of ISOC1 and miR-4633 in lung cancer development were investigated using cell proliferation, migration, and invasion assays. Xenograft tumor growth assays in nude mice were further assessed the effect of ISOC1 in the tumorigenesis of NSCLC in vivo. Cell cycle distribution analysis was performed to uncover the underlying mechanism of ISOC1 and miR-4633 in promoting NSCLC cell proliferation. Co-immunoprecipitation combined with mass spectrometry and RNA sequencing were performed to uncover the potential mechanism of ISOC1 in lung cancer development.ResultsOur results found that ISOC1 expression was upregulated in NSCLC tissues and that increased expression of ISOC1 was significantly associated with worse disease-free survival in NSCLC patients. Overexpression of ISOC1 could increase the proliferation, viability, migration, and invasion of NSCLC cells. Furthermore, miR-4633, located in the first intron of ISOC1, could also promote tumor cell progression and metastasis. Mice xenograft tumor assay showed that knockout of ISOC1 could significantly inhibit tumor growth in vivo. Besides, co-immunoprecipitation combined with mass spectrometry assay revealed that ISOC1 interacted with the proteins of DNA damage repair pathways and that upregulated ISOC1 expression could significantly increase the number of DNA damage lesions. RNA sequencing analysis showed that the downstream signaling pathways mediated by ISOC1 were mainly inflammation-related.ConclusionsWe demonstrated that ISOC1 and its intronic miR-4633, both of them could promote NSCLC cell proliferation, migration, invasion, and cell cycle progression. ISOC1 participates in DNA damage repair and inflammation to promote lung cancer development.

Cancer-derived exosomal miR-7641 promotes breast cancer progression and metastasis

BackgroundIntercellular communication is crucial for breast cancer progression and metastasis. However, the role of cancer-derived exosomes and their crucial microRNA (miRNA) cargoes mediating intercellular communication requires further investigation.MethodsCancer-derived exosomes were isolated using differential centrifugation and differentially expressed miRNAs were determined by microarrays and qRT-PCR analysis. Cell proliferation, wound-healing, Transwell invasion, and tumor xenograft assays were used for functional research. Plasma exosomal RNA was isolated to verify its role as a prognostic biomarker.ResultsWe found that the tumor-promoting capacity of the exosomes was positively related to their cells of origin. MiR-7641 was identified to be the most differentially expressed miRNA, both at endogenous and secretory levels in high-metastatic cancer cells. MiR-7641 could promote tumor cell progression and metastasis, and that these functions of miR-7641 could alter recipient cells via transportation of exosomes. Additionally, exosomal miR-7641 could promote tumor growth in vivo; and its levels were significantly elevated in the plasma of patients with distant metastasis. Bioinformatics analysis has suggested that miR-7641 is correlated with breast cancer survival, and several important cellular and biological processes are closely targeted by miR-7641.ConclusionThe findings indicate miR-7641 to be an important component of the cancer exosomes in promoting tumor progression and metastasis via intercellular communication. Additionally, exosomal miR-7641 may serve as a promising non-invasive diagnostic biomarker and potential targetable candidate in breast cancer treatment.BWySRQX9DMANyj4v-XQwBNVideo

Abstract PS19-02: Gut pathogen, Bacteroides fragilis promotes breast cancer liver and lung metastasis

Abstract Background: The last decade established significant contributions of microbiome to many organ specific cancers. Existence of distinct breast microbiota has been recently established but their biological impact in breast cancer progression remains elusive. A few recent studies suggested the existence of distinct breast microbiota and a shift in microbial community composition in diseased breast compared to normal breast however, their functional impact and underlying mechanisms are unknown. Present study was designed to examine the contribution of pro-carcinogenic bacteria in breast cancer initiation, progression and metastasis. Utilizing extensive data mining and metagenomic analyses, we discovered the presence of toxin producing enterotoxigenic Bacteroides fragilis (ETBF) in malignant breast. ETBF is a pro-carcinogenic bacteria known for its potential to initiate and/or promote colon cancer and its pathogenicity has been attributed to its unique toxin B. fragilis toxin (BFT)’. Results: Using mammary intraductal model we discovered that ETBF can successfully colonize the breast confirmed by qPCR and Fluorescent in situ hybridization where it induces local inflammation, fibrosis and hyperproliferation of breast epithelial cells. Mice bearing gut ETBF infection exhibit significant circulating BFT confirmed by qPCR and ELISA and distinct morphological alterations in mammary gland as observed from whole breast mounting and histological evaluation. Gut colonization with ETBF rapidly induces hyperplasia in mammary glands with systemic and local breast inflammation validated by flow cytometry, immunohistochemistry and cytokine profiling. While no changes are observed in cell growth and clonogenicity upon BFT treatment, significant increase in migration and invasion potential and decreased adhesion of MCF10A and MCF7 cells are observed. BFT leads to prominent cytoskeletal reorganization, and increase in migration, invasion and stemness potential of breast cancer cells. Our results indicate that breast cancer cells exposed to BFT ensue to exhibit increase tumor growth, form multifocal tumors and show a striking increase in tumor-initiating cells upon in vivo limiting dilution in immunocompromised mice exhibiting retention of ‘BFT memory’ from the initial exposure. Mechanistically, RNA-sequencing shows enrichment of βcatenin and Notch pathway in secondary tumors derived from BFT-exposed breast cancer cells. Inhibitors of βcatenin and Notch axis abrogates BFT-induced migration and invasion potential indicating the functional importance of this axis. Intriguingly, gut colonization with ETBF at a physiologically relevant level strongly induces growth and metastatic progression of 4T1 tumor cells implanted in mammary ducts monitored by whole animal bioluminescent imaging. In vivo and ex vivo analyses of tumors and distant organs reveal a significant induction of lung and liver metastasis of breast cancer by ETBF while gut colonization with non-toxigenic Bacteroides fragilis (NTBF) does not exhibit any tumor-augmenting impact. We mechanistically evaluate the oncogenic impact of alpha bug ETBF on breast cancer progression and its role in promoting liver and lung metastasis using multiple mice models and multiple techniques including multi-color flow cytometry, immunohistochemistry, quantitative PCR, multiplexed ELISA, ex vivo functional assays and western blotting. Conclusion: Collectively, these findings present the first evidence to show that gut colonization with Bacteroides fragilis rapidly induces inflammation, fibrosis and hyperplasia in the breast. In syngeneic breast cancer model, gut colonization with ETBF aggravates breast cancer progression and induces enhanced lung and liver metastasis via systemic immune modulation, cytokine synthesis and activation of pro-oncogenic pathways. Citation Format: Sheetal Parida, Sumit Siddharth, Guannan Wang, Himavanth Gatla, Shaoguang Wu, Brian Ladle, Kathleen Gabrielson, Cynthia L Sears, Dipali Sharma. Gut pathogen, Bacteroides fragilis promotes breast cancer liver and lung metastasis [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS19-02.