Inhibited Cancer Invasion Research Articles

Anticancer Potential of Quercetin on Oral Squamous Cell Carcinoma: A Scoping Review and Molecular Docking.

Oral squamous cell carcinoma (OSCC) is a type of cancer that has a low survival rate and high recurrence and metastasis rates. To date, there is still no effective treatment for OSCC. Various types of cancer, including OSCC, have reported quercetin to act as an anticancer agent, but there is no clear research data on how it may affect OSCC. To determine the anticancer potential of quercetin in OSCC, we conducted a scoping review, and to determine the interaction of quercetin with one of the proteins that plays a role in carcinogenesis, namely, BCL-2, we conducted molecular docking. The scoping review process was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews. The scoping review was searched by collecting articles related to the research topic in Google Scholar, PubMed, ScienceDirect, Cochrane, and EBSCOhost databases. All of the literature records found during the search were imported into the Mendeley software to remove duplication. Nine studies were generated after the titles and abstracts were reviewed according to the inclusion and exclusion criteria. After the full-text screening, no studies were excluded, leaving nine publications determined to be eligible for inclusion in the scoping review. Quercetin showed effects on inhibiting cancer invasion, migration, proliferation, and many protein expressions, as well as increasing cell apoptosis. Molecular docking was done for quercetin and BCl-2 protein. Doxorubicin was utilized as a comparison ligand. The in silico study was utilized using AutoDock Vina, AutoDock Tools 1.5.6, Biovia Discovery Studio 2021, and PyMol. Molecular docking indicated quercetin has a strong binding affinity with BCl-2 protein (ΔG -7.2 kcal/mol). Both scoping review and molecular docking revealed that quercetin is a promising candidate for anticancer agent.

Genotoxic and Anti-Migratory Effects of Camptothecin Combined with Celastrol or Resveratrol in Metastatic and Stem-like Cells of Colon Cancer.

Background: Colorectal cancer is one of the leading and most lethal neoplasms. Standard chemotherapy is ineffective, especially in metastatic cancer, and does not target cancer stem cells. A promising approach to improve cancer treatment is the combination therapy of standard cytostatic drugs with natural compounds. Several plant-derived compounds have been proven to possess anticancer properties, including the induction of apoptosis and inhibition of cancer invasion. This study was focused on investigating in vitro the combination of camptothecin (CPT) with celastrol (CEL) or resveratrol (RSV) as a potential strategy to target metastatic (LOVO) and stem-like (LOVO/DX) colon cancer cells. Methods: The genotoxic effects that drive cancer cells into death-inducing pathways and the ability to inhibit the migratory properties of cancer cells were evaluated. The γH2AX+ assay and Fast-Halo Assay (FHA) were used to evaluate genotoxic effects, the annexin-V apoptosis assay to rate the level of apoptosis, and the scratch test to assess antimigratory capacity. Results: The results showed that both combinations CPT-CEL and CPT-RSV improve general genotoxicity of CPT alone on metastatic cells and CSCs. However, the assessment of specific double-stranded breaks (DSBs) indicated a better efficacy of the CPT-CEL combination on LOVO cells and CPT-RSV in LOVO/DX cells. Interestingly, the combinations CPT-CEL and CPT-RSV did not improve the pro-apoptotic effect of CPT alone, with both LOVO and LOVO/DX cells suggesting activation of different cell death mechanisms. Furthermore, it was found that the combinations of CPT-CEL and CPT-RSV improve the inhibitory effect of camptothecin on cell migration. Conclusions: These findings suggest the potential utility of combining camptothecin with celastrol or resveratrol in the treatment of colon cancer, including more aggressive forms of the disease. So far, no studies evaluating the effects of combinations of these compounds have been published in the available medical databases.

The periosteum provides a stromal defence against cancer invasion into the bone.

The periosteum is the layer of cells that covers nearly the entire surface of every bone. Upon infection, injury or malignancy the bone surface undergoes new growth-the periosteal reaction-but the mechanism and physiological role of this process remain unknown1,2. Here we show that the periosteal reaction protects against cancer invasion into the bone. Histological analyses of human lesions of head and neck squamous cell carcinomas (HNSCCs) show that periosteal thickening occurs in proximity to the tumour. We developed a genetically dissectible mouse model of HNSCC and demonstrate that inducible depletion of periosteal cells accelerates cancerous invasion of the bone. Single-cell RNA sequencing reveals that expression of the gene encoding the protease inhibitor TIMP1 is markedly increased in the periosteum at the pre-invasive stage. This increase is due to upregulation of HIF1α expression in the tumour microenvironment, and increased TIMP1 inactivates matrix-degrading proteases, promoting periosteal thickening to inhibit cancer invasion. Genetic deletion of Timp1 impairs periosteal expansion, exacerbating bone invasion and decreasing survival in tumour-bearing mice. Together, these data show that the periosteal reaction may act as a functional stromal barrier against tumour progression, representing a unique example of tissue immunity mediated by stromal cells.

Effect of tocotrienol and tocopherol regulation by the microbiome on colitis-associated cancer.

e15512 Background: The association between inflammatory bowel disease (IBD) and a higher risk of colorectal cancer (CRC) has been well established, and is commonly attributed to chronic inflammation and a predisposition to genomic instability ( Feagins et al., 2009 ). Independently, an altered gut microbiome has been evidenced in both IBD ( Halfvarson et al., 2017 ) and CRC ( Marchesi et al., 2011 ). It is unknown whether the altered the IBD-associated microbiome is able to directly influence carcinogenesis via an inflammation-independent mechanisms. Methods: Microbiome analysis was performed using BioCorteX’s industry-leading knowledge graph and integrated proprietary engines v20240126_153156. 2,081 stool samples from adults with IBD and 2,000 stool samples from healthy adults were included. Shannon’s Diversity Index was used to consider within-sample diversity, and PERMANOVA and dimensional scaling based (MDS) on Bray-Curtis diversity was used to consider between-sample diversity. Differential abundance analysis was used to identify species significantly associated with IBD, and a database built on existing literature was used to consider their metabolic products and interactions with known human oncogenes and tumour suppressor genes. Results: Our results show a clearly separation of the IBD microbiome from the healthy population (PERMANOVA p = 0.01), as well as a collapse in Shannon diversity (p < 2.2e-16). Compared to the healthy microbiome, 79 species were significantly (FDR < 0.01) enriched in the IBD stool microbiome, including: Bacteroides fragilis, Bacteroides vulgatus, Bacteroides uniformis, Escherichia coli, Veillonella parvula, Enterococcus faecalis, Fusobacterium mortiferum, and Fusobacterium ulcerans, all of which have previously been evidenced to be enriched in CRC ( Randa et al., 2023 , Bi et al., 2022 , Du et al., 2022 ). Conversely, 115 species were enriched in healthy subjects, including several bacteria with probiotic and anti-tumourigeneic potential such as: Segatella copri, Roseburia inulinivorans, Lactobacillus rogosae, and Coprococcus comes ( Sarah et al., 2022 , Kang et al., 2023 , Campisciano et al., 2020 , Yang et al., 2019 ) Two of the bacteria enriched in the healthy group are producers of both delta-tocotrienol and gamma-tocopherol. These vitamin E isoforms have been implicated in suppression of cancer invasion and proliferation ( Ya et al., 2008 ), in part through NFkB signalling ( Ling et al., 2012 ). Conclusions: This work suggests that that IBD-associated microbiome may contribute to colorectal cancer risk via the suppression of vitamin E isoform signalling, a mechanism that is independent from inflammation. This could present a highly targetable way of mediating CRC-risk in the IBD population.

Role of midazolam on cancer progression/survival - An updated systematic review.

Cancer is a leading cause of mortality worldwide. Despite advancements in cancer management, cancer progression remains a challenge, requiring the development of novel therapies. Midazolam is a commonly used adjunct to anaesthesia care for various surgeries, including cancer. Recently, there has been a growing interest in exploring the potential role of midazolam as an anticancer agent; however, the exact mechanism of this linkage is yet to be investigated thoroughly. Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline, this systematic review presented aggregated evidence (till November 2022) of the effects of midazolam on cancer progression and survival. All primary research article types where midazolam was administered in vivo or in vitro on subjects with cancers were included. No restrictions were applied on routes of administration or the type of cancer under investigation. Narrative synthesis depicted qualitative findings, whereas frequencies and percentages presented numerical data. Of 1720 citations, 19 studies were included in this review. All articles were preclinical studies conducted either in vitro (58%, 11/19) or both in vivo and in vitro (42%, 8/19). The most studied cancer was lung carcinoma (21%, 4/19). There are two main findings in this review. First, midazolam delays cancer progression (89%, 17/19). Second, midazolam reduces cancer cell survival (63%, 12/19). The two major mechanisms of these properties can be explained via inducing apoptosis (63%, 12/19) and inhibiting cancer cell proliferation (53%, 10/19). In addition, midazolam demonstrated antimetastatic properties via inhibition of cancer invasion (21%, 4/19), migration (26%, 5/19), or epithelial-mesenchymal transition (5%, 1/19). These anticancer properties of midazolam were demonstrated through different pathways when midazolam was used alone or in combination with traditional cancer chemotherapeutic agents. This systematic review highlights that midazolam has the potential to impede cancer progression and decrease cancer cell survival. Extrapolation of these results into human cancer necessitates further investigation.

Intense nano-pulse stimulation-induced dynamic changes in vesicle trafficking visualized by super-resolution fluorescence microscopy

Super-resolution fluorescence microscopy (SRFM) has revolutionized biomedical research by providing valuable information at the nanometer-scale within cells. Recent advances in SRFM enable researchers to probe dynamic processes in living cells with unprecedented spatiotemporal resolution. Vesicle trafficking plays a critical role in tumor proliferation and invasion. Understanding the dynamics of vesicle trafficking in cancer cells is essential for cancer therapy. This study visualized and quantified changes in vesicle trafficking dynamics in cancer cells induced by intense nano-pulse stimulation (NPS) using SRFM. As an emerging physical modality for cancer therapy, it remains unknown whether and how NPS affects vesicle trafficking during its interaction with cancer cells. Our results indicate that NPS decreases the number, velocity, and track length of vesicles while significantly increasing the average size of vesicles. Notably, vesicle trafficking between cancer cells and normal human lung bronchial epithelial cells was also inhibited. This study provides experimental evidence that NPS directly affects vesicle trafficking. Furthermore, the results of this study may shed light on a better understanding of the mechanism by which NPS inhibits cancer invasion and metastasis. Finally, this work provides a potential physical method to regulate vesicle transport.

Folylpolyglutamate synthetase mRNA G-quadruplexes regulate its cell protrusion localization and enhance a cancer cell invasive phenotype upon folate repletion

BackgroundFolates are crucial for the biosynthesis of nucleotides and amino acids, essential for cell proliferation and development. Folate deficiency induces DNA damage, developmental defects, and tumorigenicity. The obligatory enzyme folylpolyglutamate synthetase (FPGS) mediates intracellular folate retention via cytosolic and mitochondrial folate polyglutamylation. Our previous paper demonstrated the association of the cytosolic FPGS (cFPGS) with the cytoskeleton and various cell protrusion proteins. Based on these recent findings, the aim of the current study was to investigate the potential role of cFPGS at cell protrusions.ResultsHere we uncovered a central role for two G-quadruplex (GQ) motifs in the 3′UTR of FPGS mediating the localization of cFPGS mRNA and protein at cell protrusions. Using the MBSV6-loop reporter system and fluorescence microscopy, we demonstrate that following folate deprivation, cFPGS mRNA is retained in the endoplasmic reticulum, whereas upon 15 min of folate repletion, this mRNA is rapidly translocated to cell protrusions in a 3′UTR- and actin-dependent manner. The actin dependency of this folate-induced mRNA translocation is shown by treatment with Latrunculin B and inhibitors of the Ras homolog family member A (RhoA) pathway. Upon folate repletion, the FPGS 3′UTR GQs induce an amoeboid/mesenchymal hybrid cell phenotype during migration and invasion through a collagen gel matrix. Targeted disruption of the 3′UTR GQ motifs by introducing point mutations or masking them by antisense oligonucleotides abrogated cell protrusion targeting of cFPGS mRNA.ConclusionsCollectively, the GQ motifs within the 3′UTR of FPGS regulate its transcript and protein localization at cell protrusions in response to a folate cue, inducing cancer cell invasive phenotype. These novel findings suggest that the 3′UTR GQ motifs of FPGS constitute an attractive druggable target aimed at inhibition of cancer invasion and metastasis.

Possible Action of Olaparib for Preventing Invasion of Oral Squamous Cell Carcinoma In Vitro and In Vivo.

Despite recent advances in treatment, the prognosis of oral cancer remains poor, and prevention of recurrence and metastasis is critical. Olaparib is a PARP1 inhibitor that blocks polyADP-ribosylation, which is involved in the epithelial–mesenchymal transition (EMT) characteristic of tumor recurrence. We explored the potential of olaparib in inhibiting cancer invasion in oral carcinoma using three oral cancer cell lines, HSC-2, Ca9-22, and SAS. Olaparib treatment markedly reduced their proliferation, migration, invasion, and adhesion. Furthermore, qRT-PCR revealed that olaparib inhibited the mRNA expression of markers associated with tumorigenesis and EMT, notably Ki67, Vimentin, β-catenin, MMP2, MMP9, p53, and integrin α2 and β1, while E-Cadherin was upregulated. In vivo analysis of tumor xenografts generated by injection of HSC-2 cells into the masseter muscles of mice demonstrated significant inhibition of tumorigenesis and bone invasion by olaparib compared with the control. This was associated with reduced expression of proteins involved in osteoclastogenesis, RANK and RANKL. Moreover, SNAIL and PARP1 were downregulated, while E-cadherin was increased, indicating the effect of olaparib on proteins associated with EMT in this model. Taken together, these findings confirm the effects of olaparib on EMT and bone invasion in oral carcinoma and suggest a new therapeutic strategy for this disease.

The Role of WAVE2 Signaling in Cancer.

The Wiskott–Aldrich syndrome protein (WASP) and WASP family verprolin-homologous protein (WAVE)—WAVE1, WAVE2 and WAVE3 regulate rapid reorganization of cortical actin filaments and have been shown to form a key link between small GTPases and the actin cytoskeleton. Upon receiving upstream signals from Rho-family GTPases, the WASP and WAVE family proteins play a significant role in polymerization of actin cytoskeleton through activation of actin-related protein 2/3 complex (Arp2/3). The Arp2/3 complex, once activated, forms actin-based membrane protrusions essential for cell migration and cancer cell invasion. Thus, by activation of Arp2/3 complex, the WAVE and WASP family proteins, as part of the WAVE regulatory complex (WRC), have been shown to play a critical role in cancer cell invasion and metastasis, drawing significant research interest over recent years. Several studies have highlighted the potential for targeting the genes encoding either part of or a complete protein from the WASP/WAVE family as therapeutic strategies for preventing the invasion and metastasis of cancer cells. WAVE2 is well documented to be associated with the pathogenesis of several human cancers, including lung, liver, pancreatic, prostate, colorectal and breast cancer, as well as other hematologic malignancies. This review focuses mainly on the role of WAVE2 in the development, invasion and metastasis of different types of cancer. This review also summarizes the molecular mechanisms that regulate the activity of WAVE2, as well as those oncogenic pathways that are regulated by WAVE2 to promote the cancer phenotype. Finally, we discuss potential therapeutic strategies that target WAVE2 or the WAVE regulatory complex, aimed at preventing or inhibiting cancer invasion and metastasis.

Novel Thyrointegrin αvβ3 Antagonist for the Effective Management of Acute Myeloid Leukemia

Acute myeloid leukemia is one of the most aggressive malignant hematological disorders on worldwide basis. More than 19,000 new cases are estimated in the United States in 2020 (1.1% of all new cancer cases). The estimated death rate from AML is 11,180 that represent 56% of the new cases (1.8% of all cancer death), with an overall 5-year survival rate of 27.4% [1]. Current treatment regimens for AML include traditional chemotherapy, radiotherapy, allogeneic hematopoietic cell transplantation and targeted therapies for specific mutations in limited numbers of AML patients, all of whom still suffer from adverse effects and relapse. New broad spectrum effective and safe treatment options are urgently needed for the different types of AML. Our strategy focused on developing a novel targeted therapy for the thyrointegrin αvβ3 receptors that are over-expressed in leukemic cells. This receptors support adhesion, engraftment, proliferation, invasion/metastasis, and angiogenesis functions of leukemic cells. The identified thyrointegrin αvβ3 antagonist fluorobenzyl Polyethylene glycol Mono-Triazole Tetraiodothyroacetic Acid (fb-PMT) binds with high affinity and specificity. Our study showed that fb-PMT effectively suppresses the functions of AML cell line and primary cell harboring FLT3-ITD after successful engraftment in transgenic NSG-S xenograft mouse models. Daily treatment with fb-PMT at doses ranging from 1-10 mg/kg, subcutaneously for 3-4 weeks were associated with leukemogenesis regression, suppression of cancer invasion and extended survival in both models. These findings were verified using IVIS scanning and histopathological examination to evaluate the engraftment of leukemic cells in the bone marrow and other organs including, spleen, liver, lung, and brain. Furthermore, fb-PMT at 3 and 10 mg/kg, s.c. daily for 3-4 weeks exhibited significant reduction (P<0.001) of leukemic cell burden 74% and >95%, respectively. Peripheral blood smears from fb-PMT treated animals were reversed back to normal with no blast cells along with normal cell counts. Bone marrow regain its normal maturation with abundant segmented neutrophil and megakaryocytes, representing complete hematological remission along with complete suppression of leukemic cell metastasis and invasion into different organs. To evaluate the relapse after treatment, 40 mice were maintained off treatment for further 2 weeks and IVIS scans and peripheral blood smear examination were performed on animals at end of first week and at sacrifice. The fb-PMT (10 mg/kg) off treatment has shown successful maintained remission after stopping the daily treatment as confirmed using blood smear examination, IVIS scan, and histopathological examination. Additionally, safety assessments in rodents and monkeys demonstrated safety and tolerability at multiple folds above the anticipated human doses. Lastly, our genome-wide microarray screen demonstrated that fb-PMT works through the Hedgehog pathway and Il-21 receptor down-regulation as well as downregulation of several genes including, IGF2, TWIST1 and FYN oncogene, angiopoietin 1 (ANGPT1), angiopoietin-like 2 (ANGPTL2) and PIM1 oncogene KIT, HRAS, INH2, BCL, AKT1, IDH2, CDK4/6, TIMP1, VEGF, EGFR and PD-L1, KDM6A, EZH2. Collectively, preclinical findings of fb-PMT warrant its clinical investigation for the effective and safe management of AML. Reference 1. Key Statistics for Acute Myeloid Leukemia (AML). 2020; Available from: https://www.cancer.org/cancer/acute-myeloid-leukemia/about/key-statistics.html. Figure 1 Disclosures Mousa: Vascular Vision Pharma Co.: Patents & Royalties.

NKX6.1 Represses Tumorigenesis, Metastasis, and Chemoresistance in Colorectal Cancer.

Accumulating evidence suggests that NKX6.1 (NK homeobox 1) plays a role in various types of cancer. In our previous studies, we identified NKX6.1 hypermethylation as a promising marker and demonstrated that the NKX6.1 gene functions as a metastasis suppressor through the epigenetic regulation of the epithelial-to-mesenchymal transition (EMT) in cervical cancer. More recently, we have demonstrated that NKX6.1 methylation is related to the chemotherapy response in colorectal cancer (CRC). Nevertheless, the biological function of NKX6.1 in the tumorigenesis of CRC remains unclear. In this study, we showed that NKX6.1 suppresses tumorigenic and metastatic ability both in vitro and in vivo. NKX6.1 represses cell invasion partly through the modulation of EMT. The overexpression of NKX6.1 enhances chemosensitivity in CRC cells. To further explore how NKX6.1 exerts its tumor-suppressive function, we used RNA sequencing technology for comprehensive analysis. The results showed that differentially expressed genes (DEGs) were mainly related to cell migration, response to drug, transcription factor activity, and growth factor activity, suggesting that these DEGs are involved in the function of NKX6.1 suppressing cancer invasion and metastasis. Our results demonstrated that NKX6.1 functions as a tumor suppressor partly by repressing EMT and enhancing chemosensitivity in CRC, making it a potential therapeutic target.

Targeting the C-Terminal Domain Small Phosphatase 1.

The human C-terminal domain small phosphatase 1 (CTDSP1/SCP1) is a protein phosphatase with a conserved catalytic site of DXDXT/V. CTDSP1’s major activity has been identified as dephosphorylation of the 5th Ser residue of the tandem heptad repeat of the RNA polymerase II C-terminal domain (RNAP II CTD). It is also implicated in various pivotal biological activities, such as acting as a driving factor in repressor element 1 (RE-1)-silencing transcription factor (REST) complex, which silences the neuronal genes in non-neuronal cells, G1/S phase transition, and osteoblast differentiation. Recent findings have denoted that negative regulation of CTDSP1 results in suppression of cancer invasion in neuroglioma cells. Several researchers have focused on the development of regulating materials of CTDSP1, due to the significant roles it has in various biological activities. In this review, we focused on this emerging target and explored the biological significance, challenges, and opportunities in targeting CTDSP1 from a drug designing perspective.

Econazole Induces p53-Dependent Apoptosis and Decreases Metastasis Ability in Gastric Cancer Cells.

Econazole, a potent broad-spectrum antifungal agent and a Ca2+ channel antagonist, induces cytotoxicity in leukemia cells and is used for the treatment of skin infections. However, little is known about its cytotoxic effects on solid tumor cells. Here, we investigated the molecular mechanism underlying econazole-induced toxicity in vitro and evaluated its regulatory effect on the metastasis of gastric cancer cells. Using the gastric cancer cell lines AGS and SNU1 expressing wild-type p53 we demonstrated that econazole could significantly reduce cell viability and colony-forming (tumorigenesis) ability. Econazole induced G0/G1 phase arrest, promoted apoptosis, and effectively blocked proliferation- and survival-related signal transduction pathways in gastric cancer cells. In addition, econazole inhibited the secretion of matrix metalloproteinase- 2 (MMP-2) and MMP-9, which degrade the extracellular matrix and basement membrane. Econazole also effectively inhibited the metastasis of gastric cancer cells, as confirmed from cell invasion and wound healing assays. The protein level of p53 was significantly elevated after econazole treatment of AGS and SNU1 cells. However, apoptosis was blocked in econazole-treated cells exposed to a p53-specific small-interfering RNA to eliminate p53 expression. These results provide evidence that econazole could be repurposed to induce gastric cancer cell death and inhibit cancer invasion.

Degradation of the Tumor Suppressor PDCD4 Is Impaired by the Suppression of p62/SQSTM1 and Autophagy.

PDCD4 (programmed cell death 4) is a tumor suppressor that plays a crucial role in multiple cellular functions, such as the control of protein synthesis and transcriptional control of some genes, the inhibition of cancer invasion and metastasis. The expression of this protein is controlled by synthesis, such as via transcription and translation, and degradation by the ubiquitin-proteasome system. The mitogens, known as tumor promotors, EGF (epidermal growth factor) and TPA (12-O-tetradecanoylphorbol-13-acetate) stimulate the degradation of PDCD4 protein. However, the whole picture of PDCD4 degradation mechanisms is still unclear, we therefore investigated the relationship between PDCD4 and autophagy. The proteasome inhibitor MG132 and the autophagy inhibitor bafilomycin A1 were found to upregulate the PDCD4 levels. PDCD4 protein levels increased synergistically in the presence of both inhibitors. Knockdown of p62/SQSTM1 (sequestosome-1), a polyubiquitin binding partner, also upregulated the PDCD4 levels. P62 and LC3 (microtubule-associated protein 1A/1B-light chain 3)-II were co-immunoprecipitated by an anti-PDCD4 antibody. Colocalization particles of PDCD4, p62 and the autophagosome marker LC3 were observed and the colocalization areas increased in the presence of autophagy and/or proteasome inhibitor(s) in Huh7 cells. In ATG (autophagy related) 5-deficient Huh7 cells in which autophagy was impaired, the PDCD4 levels were increased at the basal levels and upregulated in the presence of autophagy inhibitors. Based on the above findings, we concluded that after phosphorylation in the degron and ubiquitination, PDCD4 is degraded by both the proteasome and autophagy systems.

Small interfering RNA targeting paul-like kinase 1 gene silencing inhibits colon cancer invasion and proliferation in clinical, cellular and mouse studies

Objective To investigate the clinical, cellular and mouse studies of small interfering RNA (siRNA) targeting silencing of paul-like kinase 1 (PLK1) on colon cancer invasion and proliferation. Methods Sixty-eight patients with colon cancer admitted to the Second Affiliated Hospital of Hainan Medical College from July 2013 to September 2018 were enrolled, including 40 males and 28 females. The average age was (47.5±6.2) years. Western blotting and real-time quantitative PCR (RT-qPCR) were used to detect PLK1 protein and mRNA levels, respectively. In vitro invasion assay (Transwell) and cell proliferation and toxicity (CCK-8) assays detect cell invasion and proliferation. A subcutaneous xenograft nude mouse colon cancer model was constructed for animal experiments. The F-test was used to compare the measurement data among groups, and the t-test was used for the comparison between the two groups. The rate was compared using the χ2 test. Correlation analysis was performed using the Spearman method. Results Compared with adjacent tissues (8.72±2.19), the mRNA level of PLK1 in colon cancer tissues (15.34±3.86) was significantly increased (t=12.593, P<0.05). The level of PLK1 was positively correlated with tumor invasion depth (r=0.368, P<0.05) and TNM stage (r=0.403, P<0.05). Compared with the siRNA negative control [invasion: (37.20±4.50)], the invasive ability of SW480 cells was significantly decreased after PLK1-siRNA-1 [invasion: (15.00±3.75)] and PLK1-siRNA-2 [invasion: (14.60±3.40)] treatments (t=5.073, t=4.985, P<0.05). At 24 h, 48 h, and 72 h, compared to the siRNA negative control [absorbance (A) values: 0.53±0.12, 0.73±0.16, 0.86±0.18], the proliferation of PLK1-siRNA-1 (0.32±0.10, 0.40±0.08, 0.53±0.10) and PLK1-siRNA-2 (0.34±0.08, 0.41±0.09, 0.54±0.11) decreased significantly (t=4.167, t=4.990, t=4.833, t=4.001, t=4.708, t=4.665, P<0.05). Compared with the siRNA negative control [tumor volume: (849.12±65.37) mm3; number of nodules: (9.35±2.15)], the mean tumor volume and the number of tumor nodules in nude mice treated with PLK1-siRNA-1 [tumor volume: (135.06±9.11) mm3; number of nodules: 1.46±0.20] and PLK1-siRNA-2 [tumor volume: (127.45±8.86) mm3; number of nodules: (1.30±0.15)] were significantly lower (t=19.168, t=7.004, t=20.365, t=7.659, P<0.05). Conclusion Targeted silencing of PLK1 can inhibit the invasion and proliferation of colon cancer, and provide a theoretical basis for the targeted prevention and treatment of colon cancer. Key words: Colon cancer; Paul-like kinase 1; Invasion; Proliferation

Abstract 291: Synergistic inhibition of cancer invasion and metastasis by combined anti-PD1-TRC105-mediated Endoglin targeting on cancer-associated fibroblasts and endothelial cells

Abstract Cancer-associated fibroblasts (CAFs) are the major component of the tumor microenvironment in colorectal cancer (CRC) and play an important role in tumor progression and metastasis, partly through the transforming growth factor-β (TGF-β) signaling pathway. Recently, we showed that a subset of CAFs characterized by the expression of the TGF-β family co-receptor endoglin, selectively localized at the invasive borders of CRC tissues. Moreover, CAF-specific endoglin expression increased with higher tumor stage and predicted metastasis-free survival of stage-II CRC patients (n= 140, p&amp;lt;0.05). Targeting endoglin on CAFs using TRC105 (carotuximab), an endoglin neutralizing antibody currently in clinical development, inhibits endoglin dependent signaling and metastatic colonization when CRC cells and CAFs are co-injected into mice. We further investigated these anti-tumor effects in four different models of CRC (chemically-induced model of early CRC, subcutaneous MC38 and CT26 syngeneic mouse CRC models, and orthotopic MC38 model). TRC105 treatment inhibited tumor initiation (early stage CRC), growth, and progression. Therapeutic effects of TRC105 therapy were dependent on antibody dependent cytotoxicity (ADCC) and CD8+ T-cells, as no therapeutic benefit from TRC105 was observed in Fc-y I-IV receptor knockout mice or CD8+ cell depleted mice. Since therapeutic TRC105 activity was immune cell dependent, we combined TRC105 with anti-programmed cell death (PD-1 immunotherapy). We observed synergistic inhibition of tumor initiation and growth in all four tumor models, leading to delayed tumor outgrowth, increased survival and cure rates up to 60% in the combination treated mice bearing palpable tumors. Combined treatment also induced memory responses, as shown by resistance to repeated tumor challenge. Anti-tumor responses were accompanied by enhanced immune cell activation including an increased number of tumor-specific T-cells, NK cells, decreased number of tumor-infiltrating neutrophils and increased granzyme B production. CD8+ cytotoxic T-cells were instrumental in these synergistic therapeutic responses, as their depletion abolished the effects. Taken together, our data indicate significant therapeutic effects of targeting endoglin by affecting signaling and multiple immune related components in the tumor microenvironment. These results are currently being translated in a clinical trial combining TRC105 with nivolumab in patients with non-small cell lung cancer (NCT03181308). Citation Format: Mark JA Schoonderwoerd, Madelon Paauwe, Ricardo Angela, Maaike Koops, Tom Harryvan, Cornelis Sier, Marieke Fransen, Charles Theuer, Lukas JAC Hawinkels. Synergistic inhibition of cancer invasion and metastasis by combined anti-PD1-TRC105-mediated Endoglin targeting on cancer-associated fibroblasts and endothelial cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 291.

157 Uncharacterized protein REDI is required for epidermal differentiation and suppression of cancer invasion

Cutaneous squamous cell carcinoma (SCC) often demonstrates loss of epidermal differentiation that is regulated by an ever-increasing number of genes. REDI (Regulator of Epidermal Differentiation and Invasion) is a previously uncharacterized protein that we show controls skin differentiation and functions as a tumor suppressor in SCC. We identified REDI in an RNAseq-based screen for uncharacterized open reading frames with opposite patterns of expression in human SCC and keratinocyte differentiation. REDI is necessary and sufficient for epidermal differentiation; CRISPR/Cas9-mediated depletion of REDI in organotypic human epidermal tissue attenuates differentiation, while enforcing REDI expression enhances it. Proximity-dependent biotin identification was performed in organotypic skin tissue to distill REDI’s interactors and highlighted calcyclin binding protein (CACYBP), a protein not previously implicated in epidermal differentiation. Depletion of CACYBP phenocopies REDI loss and reduces differentiation in human skin tissue. Whole transcriptome analysis confirms that REDI and CACYBP co-control a significant subset of genes involved in keratinization, skin differentiation and development. Given REDI downregulation in SCC and its deletion in 21 TCGA cancer types, we evaluated the impact of REDI gain- and loss-of-function in organotypic human skin tissue programmed to transform into invasive epidermal neoplasia. REDI deletion enhances the extent and depth of invasion of Ras-transformed keratinocytes across the basement membrane, while enforced expression of REDI profoundly blocks early tumor progression. In each case, expression of REDI and the proto-oncogene c-RET are negatively correlated. Efforts are underway to confirm whether pharmacologic inhibition of c-RET offsets the impacts of REDI deletion on neoplastic invasion. Drug repurposing to identify a REDI mimic highlights HDAC inhibitors and inhibitors of PI3K/Akt as potential therapeutic candidates.

Epigenetic silencing of Rab39a promotes epithelial to mesenchymal transition of cervical cancer through AKT signaling

The objective of this study was to investigate the functional role of Rab39a in human cervical cancer (CC) and the underlying molecular mechanisms. We first measured Rab39a mRNA expression in CC tissues and paired non-tumor tissues by quantitative real-time PCR (QRT-PCR). Overall survival of CC patients with different mRNA levels of Rab39a in The Cancer Genome Atlas (TCGA) database was assessed by Kaplan-Meier survival curves analysis. Next methylation-specific PCR (MSP) was performed to determine the expression mechanism of Rab39a. Then cell proliferation, migration and invasion of Rab39a-transfected or mock-transfected cervical cancer cells were determined by CCK-8, flow cytometry, wound healing, transwell migration and invasion assays, respectively. Finally, the molecular mechanism by which Rab39a modulated CC cell epithelial-mesenchymal transition (EMT) was explored. It was found that Rab39a mRNA was significantly down-regulated in the high-risk patients compared to the low-risk patients (p = 0.0054). Six of seven cancer tissues with lymph node metastasis express low Rab39a mRNA compared to the surrounding non-tumor tissues. Cervical cancer patients with low level of Rab39a were showed a poorly clinical outcome (p = 0.004). Loss of Rab39a expression in cervical cancer tissues was associated with the aberrant DNA methylation in the promoter of Rab39a gene. Disrupted Rab39a expression in cervical cancer cells could be restored after treatment with the demethylated agent 5-Aza-2'-deoxycytidine. Furthermore, it was found that Rab39a hardly influenced cell growth but significantly suppressed cell migration, invasion and EMT process. Rab39a exerted its potential suppressor functions through inhibiting AKT phosphorylation. The inhibition effects of Rab39a could be blocked by AKT pathway inhibitor. Collectively, our data shows that Rab39a is a potential epigenetic silenced tumor suppressor inhibiting cancer invasion and migration through modulating the AKT signaling.

Perspectives of Plant Natural Products in Inhibition of Cancer Invasion and Metastasis by Regulating Multiple Signaling Pathways.

Metastasis is often derived from increased invasion and migration of tumor cells, and is the most frequent cause of cancer-associated death. Either the prophylactic or therapeutic treatment of metastatic cancer remains very challenging today by virtue of the complex histopathology and genetic or epigenetic variations. Medicinal scientists had discovered many potential anti-invasive and anti-metastatic compounds from plant materials. However, data on currently available plant-based compounds inhibiting cancer invasion and metastasis is relatively scanty and no published article has been found with updated information in this unique and important aspect. We obtained relevant information from a structured search of 327 peer-reviewed articles, including both research- and review-based papers, related to the use of plant materials in cancer treatments, particularly for the suppression of invasion and metastasis. We have categorized the plant-based products with anti-invasive or anti-metastatic properties into alkaloids, flavonoids, terpenes, quinones, phenolics, xanthone and sulfur-containing compounds, and complemented with their chemical structures, sources of isolation and biological targets in the present review article. We aim to provide readers a convenient way in reviewing the potential anti-invasive and anti-metastatic plant-based products with links to different mechanistic pathways, and to inspire researchers with updated information for the development of new anticancer remedies.

The Use of Naphthoquinones and Furano-naphthoquinones as Antiinvasive Agents.

Cancer is a leading cause of mortality in the world and metastasis is to blame. A number of naphthoquinones (NQs) have shown ability to reduce cancer stemness and metastatic potential. Furano-naphthoquinones (FNQs), which is a class of NQ characterized by the incorporation of an additional furan ring, have demonstrated improved anti-cancer potency as compared to the other classes of NQs. In this study, the natural origins, synthetic routes and derivatives of migrastatic NQs were reviewed. The anti-invasive and anti-metastatic mechanisms of NQs and the more powerful FNQs in targeting cancer were also discussed. The articles related to the anti-invasive mechanisms of NQs were comprehensively reviewed. The plant origins, synthetic routes and antitumor effects of more than 360 FNQs were also covered and presented according to their chemical structures. Anti-cancer NQs inhibit cancer invasion by acting on epithelial-mesenchymal transition (EMT), cancer stem cells (CSCs) and signal transducer and activator of transcription 3 (STAT3) signaling. BBI608, a natural FNQ, has entered phases I and II clinical trials. It has been regarded as a potential candidate for new-generation lead compound acting directly on CSCs to overcome the problem of chemotherapy resistance. Apart from the plant-derived FNQs, there are a number of synthetic FNQs that were found to intervene in cancer invasion and metastasis. The anti-invasive mechanisms of NQs have been thoroughly studied. FNQs generally show higher anti-cancer activity than that of NQs. The mechanisms of action of FNQs are worth further investigation.