Inhibits Tumor Invasion Research Articles

Global Research Trends and Hotspots of Autophagy in Colorectal Cancer: A 20-year Bibliometric Analysis Based on Web of Science.

Autophagy plays a pivotal role in the progression and management of colorectal cancer (CRC). Recently, numerous articles focusing on the role of autophagy in CRC have emerged. The present study was conducted to provide a comprehensive analysis of the current state and changing trends in the relationship of autophagy and CRC over the past 20 years. The Web of Science Core Collection (WOSCC) was utilized to extracted all publications with respect to autophagy and CRC during 2002-2021. The contributions of various countries/regions, institutions and journals in this field were analyzed, moreover, research hotspots and promising future trends predicted through keywords were identified by the online platform of bibliometrics, CiteSpace and VOSviewer. A total of 2418 related publications from 2002 to 2021 were identified and collected. China occupied first place with respect to the number of publications, followed by the USA and South Korea. Shanghai Jiao Tong University published the most papers in this field. Most publications were published in Oncotarget. Additionally, analysis of the keywords identified 4 clusters with various research focuses: "mechanism-related research", "clinical-related research", "tumorigenesis research" and "chemotherapy-related research". The three latest hot keywords in this field were epithelial-mesenchymal transition (EMT), promote and invasion. The number of publications and research interest on autophagy and CRC are increasing annually, and the USA had prominent academic positions in the field. Shanghai Jiao Tong University represents a high level of research and the latest progress in this field can be tracked at Oncotarget. Throughout the research history of autophagy and CRC in the past 20 years, previous studies have mainly concentrated on apoptosis and drug resistance in tumor cells, while EMT in regulating tumorigenesis and development of clinical drugs that inhibit tumor invasion through autophagy may be novel hotspots in the future.

Newly Released Advances in the Molecular Mechanisms of Osseous Metastasis and Potential Therapeutic Strategies.

The appearance of bone metastases (BM) in individuals with advanced solid cancers (breast, prostate, lung) often worsens their quality of life and prognosis. Although none have been fully effective, several strategies have been used to combat BM. Hence, the need for new data that could be useful for treating bone metastasis. To this end, we reviewed the recent literature on the subject. About patients with prostate cancer, treatments with PIP5K1α inhibitors have been found to inhibit tumor invasion and metastasis, and G protein-coupled receptor class C group 5 member A (GPRC5A) could be a future therapeutic target. Regarding patients with breast cancer, we found the following: Asperolide A could be another curative drug; targeting transforming growth factor-beta (TGFβ) and bone morphogenetic protein (BMP) signaling pathways, along with osteoclast activity, could be a favorable therapeutic approach in the preclusion of osteolytic bone destruction; TRAF6 inhibitors such as 6877002 appear promising; aiming the BMP4-SMAD7 signaling axis is an innovative therapeutic approach; there is favorable proof for the plausible therapeutic utilization of bone aiming immunostimulatory MOF (BT-isMOF) nanoparticles, and inhibition of IL4R and macrophages could have therapeutic benefits. For lung cancer, the function of LIGHT in osteolytic osseous illness instigated by metastatic non-small cell lung cancer should be highlighted.

Combination of Ad-SGE-REIC and bevacizumab modulates glioma progression by suppressing tumor invasion and angiogenesis.

Reduced expression in immortalized cells/Dickkopf-3 (REIC/Dkk-3) is a tumor suppressor and its overexpression has been shown to exert anti-tumor effects as a therapeutic target gene in many human cancers. Recently, we demonstrated the anti-glioma effects of an adenoviral vector carrying REIC/Dkk-3 with the super gene expression system (Ad-SGE-REIC). Anti-vascular endothelial growth factor treatments such as bevacizumab have demonstrated convincing therapeutic advantage in patients with glioblastoma. However, bevacizumab did not improve overall survival in patients with newly diagnosed glioblastoma. In this study, we examined the effects of Ad-SGE-REIC on glioma treated with bevacizumab. Ad-SGE-REIC treatment resulted in a significant reduction in the number of invasion cells treated with bevacizumab. Western blot analyses revealed the increased expression of several endoplasmic reticulum stress markers in cells treated with both bevacizumab and Ad-SGE-REIC, as well as decreased β-catenin protein levels. In malignant glioma mouse models, overall survival was extended in the combination therapy group. These results suggest that the combination therapy of Ad-SGE-REIC and bevacizumab exerts anti-glioma effects by suppressing the angiogenesis and invasion of tumors. Combined Ad-SGE-REIC and bevacizumab might be a promising strategy for the treatment of malignant glioma.

Pan-Cancer Analysis Reveals SH3TC2 as an Oncogene for Colorectal Cancer and Promotes Tumorigenesis via the MAPK Pathway.

Simple SummarySH3 domain and tetrapeptide repeat 2 (SH3TC2) is a protein-encoding gene and has previously been described as a critical signaling hub for neurological disorders, but no systematic analysis of SH3TC2 is available in cancer research. We analyzed SH3TC2 in various kinds of cancer to find its tumorigenic role in one or more specific cancers and further explored the mechanism of SH3TC2 in colorectal cancer (CRC). Our research revealed that higher expression of SH3TC2 indicated poor disease-free survival and promoted CRC progression and invasion via the MAPK signaling pathway.SH3 domain and tetrapeptide repeat 2 (SH3TC2) is a protein-encoding gene and has previously been described as a critical signaling hub for neurological disorders. Although increasing evidence supports a vital role of SH3TC2 in the tumorigenesis of various kinds of cancer, no systematic analysis of SH3TC2 is available. The function and mechanism of SH3TC2 in other cancers remain unknown. Thus, this study aimed to analyze SH3TC2 in various kinds of cancer to find its tumorigenic role in one or more specific cancers. In the current study, we analyzed the expression level and prognostic value of SH3TC2 in different tumors in the TCGA-GTEx pan-cancer dataset. Subsequently, the prognostic role and mechanism of SH3TC2 in colorectal cancer (CRC) were further explored via clinical samples and in vitro and in vivo experiments. We observed differential expression of SH3TC2 in colon adenocarcinoma (COAD), acute myeloid leukemia (LAML), READ (rectum adenocarcinoma), SKCM (skin cutaneous melanoma), and TGCT (testicular germ cell tumors). Subsequently, SH3TC2 showed a significant effect on the clinical stage and prognostic value in CRC, LAML, and SKCM. Moreover, we found in the TCGA database and seven GEO datasets that SH3TC2 was significantly highly expressed in tumor tissue. Through enrichment analysis of SH3TC2 and its co-expressed genes, we found that SH3TC2 may play a role in the MAPK signaling pathway. Correlation analysis indicated that SH3TC2 was significantly associated with multiple key factors in the MAPK signaling pathway. Additionally, higher expression of SH3TC2 was found in tumor tissue in our cohort including 40 CRC patients. Overexpression of SH3TC2 may imply poor prognosis. Knockdown of SH3TC2 significantly inhibited tumor invasion, migration, and proliferation. More importantly, knockdown of SH3TC2 inhibited tumor growth in a CRC mouse model. The study preliminarily conducted a pan-cancer study of SH3TC2 and further explored the mechanism of SH3TC2 in CRC. Our research revealed that higher expression of SH3TC2 may promote CRC progression and invasion via the MAPK signaling pathway.

Cordyceps militaris Reduces Oxidative Stress and Regulates Immune T Cells to Inhibit Metastatic Melanoma Invasion.

In this study, the water extract of Cordyceps militaris (Linn.) Link (CM) was used as a functional material to investigate the inhibitory mechanisms on B16F10 and lung metastatic melanoma (LMM) cells. Reducing power, chelating ability, and 2,2-diphenyl-2-picrylhydrazyl (DPPH) assays were applied for antioxidative capacities, and we obtained positive results from the proper concentrations of CM. To examine the ability of CM in melanoma proliferation inhibition and to substantiate the previous outcomes, three cellular experiments were performed via (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT, a tetrazole) assay, cell migration, and invasion evaluation. The addition of CM to the incubation medium increased the number of CD8+ T cells significantly, which improved the immunogenicity. This study showed that CM exhibits various biological capabilities, including antioxidation, anti-tumor, tumor invasion suppression, and T cytotoxic cell activity promotion.

Biosynthetic Nanobubble-Mediated CRISPR/Cas9 Gene Editing of Cdh2 Inhibits Breast Cancer Metastasis.

The epithelial-mesenchymal transition (EMT), a process in which epithelial cells undergo a series of biochemical changes to acquire a mesenchymal phenotype, has been linked to tumor metastasis. Here, we present a novel strategy for knocking out the EMT-related Cdh2 gene, which encodes N-cadherin through CRISPR/Cas9-mediated gene editing by an ultrasound combined with biosynthetic nanobubbles (Gas Vesicles, GVs). Polyethyleneimine were employed as a gene delivery vector to deliver sgRNA into 4T1 cells that stably express the Cas9 protein, resulting in the stable Cdh2 gene- knockout cell lines. The Western blotting assay confirmed the absence of an N-cadherin protein in these Cdh2 gene-knockout 4T1 cell lines. Significantly reduced tumor cell migration was observed in the Cdh2 gene-knockout 4T1 cells in comparison with the wild-type cells. Our study demonstrated that an ultrasound combined with GVs could effectively mediate CRISPR/Cas9 gene editing of a Cdh2 gene to inhibit tumor invasion and metastasis.

Anti-tumor and anti-metastatic activity of the FGF2 118-126 fragment dependent on the loop structure.

Fibroblast Growth Factor/FGF Receptor 1 (FGF2/FGFR1) system regulates the growth and metastasis of different cancers. Inhibition of this signaling pathway is an attractive target for cancer therapy. Here, we aimed to reproduce the 118-126 fragment of FGF2 to interfere with the FGF2-FGFR1 interaction. To determine whether the loop structure affects the function of this fragment, we compared cyclic (disulfide-bonded) and linear peptide variants. The cyclic peptide (referred to as BGF1) effectively inhibited the FGF2-induced proliferation of HUVECs, 4T1 mammary carcinoma, U87 glioblastoma, and SKOV3 ovarian carcinoma cells. It led to apoptosis induction in HUVECs, whereas the linear peptide (referred to as BGF2) was ineffective. In a murine 4T1 tumor model, BGF1 inhibited tumor growth more effectively than Avastin and increased animals' survival without causing weight loss, but the linear peptide BGF2 had no significant anti-tumor effects. According to immunohistochemical studies, the anti-tumor properties of BGF1 were associated with suppression of tumor cell proliferation (Ki-67 expression), angiogenesis (CD31 expression), and apoptosis induction (as was shown by increased p53 expression and TUNEL staining and decreased Bcl-2 expression). The potential of BGF1 to suppress tumor invasion was indicated by quantitative analysis of the metastasis-related proteins, including FGFR1, pFGFR1, NF-κB, p-NF-κB, MMP-9, E-cadherin, N-cadherin, and Vimentin, and supported by small animal positron emission tomography (PET) used 18Fluorodeoxyglucose (18F-FDG). These results demonstrate that the functional properties of the 118-126 region of FGF2 depend on the loop structure and the peptide derived from this fragment encourages further preclinical investigations.

Abstract 263: PIM kinase regulates actin dynamics in hypoxia

Abstract One of the leading factors in prostate cancer mortality is the onset of metastatic events. This is seen by the drastic decline in survival rates following tumor escape from the primary site. A key promoter of metastasis is tumor hypoxia, or low oxygen concentration. Our lab previously demonstrated that Proviral Integration site for Moloney murine leukemia virus (PIM)-1, a serine-threonine kinase, is upregulated in hypoxia and that inhibition of PIM1 reduced metastatic occurrence in orthotopic mouse models. Here, we identify a novel signaling pathway that links hypoxia and PIM kinase to the actin cytoskeleton and cell motility. An unbiased screen to discover new PIM substrates in hypoxia identified Abl-Interactor 2 (Abi2), an integral member of the actin regulating Wave Regulatory Complex (WRC), as a novel PIM kinase substrate. Biochemical analysis demonstrates that phosphorylation of Abi2 at our identified PIM sites increases Abi2 stability. Overexpression of PIM1 increases Abi2 and other WRC members at the protein level, resulting in increased actin protrusions and cell motility. CRISPR-generated Abi2 knockout cell lines showed diminished protrusive activity and negated both the necessity and sufficiency of PIM kinase to increases protrusive activity in cancer cells. Lastly, in vivo experiments show that overexpression of PIM1 increases tumor invasion into the surrounding tissue in an Abi2-dependent manner, and small molecule PIM inhibitors significantly reduce invasion. In summary, we uncovered a novel role for PIM1 in promoting cellular motility and protrusion, identified novel phosphorylation sites that control the stability of Abi2 in normoxic and hypoxic conditions, and highlight a novel PIM1/Abi2 signaling axis that regulates hypoxia-induced tumor invasion. This research provides important insight in the role of PIM signaling in prostate tumors and yields preclinical evidence for further use of PIM kinase inhibitors as a means to inhibit tumor invasion, a key driving step in the formation of lethal prostate cancer metastasis. Citation Format: Corbin C. Jensen, Noel A. Warfel. PIM kinase regulates actin dynamics in hypoxia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 263.

Homophilic ATP1A1 binding induces activin A secretion to promote EMT of tumor cells and myofibroblast activation

Tumor cells with diverse phenotypes and biological behaviors are influenced by stromal cells through secretory factors or direct cell-cell contact. Pancreatic ductal adenocarcinoma (PDAC) is characterized by extensive desmoplasia with fibroblasts as the major cell type. In the present study, we observe enrichment of myofibroblasts in a juxta-tumoral position with tumor cells undergoing epithelial-mesenchymal transition (EMT) that facilitates invasion and correlates with a worse clinical prognosis in PDAC patients. Direct cell-cell contacts forming heterocellular aggregates between fibroblasts and tumor cells are detected in primary pancreatic tumors and circulating tumor microemboli (CTM). Mechanistically, ATP1A1 overexpressed in tumor cells binds to and reorganizes ATP1A1 of fibroblasts that induces calcium oscillations, NF-κB activation, and activin A secretion. Silencing ATP1A1 expression or neutralizing activin A secretion suppress tumor invasion and colonization. Taken together, these results elucidate the direct interplay between tumor cells and bound fibroblasts in PDAC progression, thereby providing potential therapeutic opportunities for inhibiting metastasis by interfering with these cell-cell interactions.

E-cadherin Expression in Canine Gastric Carcinomas: Association with Clinicopathological Parameters.

E-cadherin (E-cad) is a cell-adhesion molecule known for its tumor-invasion suppressor function. E-cad expression was examined immunohistochemically in a series of canine tissue samples, including normal gastric mucosa (NGM; n = 3), gastric carcinomas (GC; n = 33), adjacent non-neoplastic mucosa (NNM; n = 32), neoplastic emboli (n = 16) and metastatic lesions (n = 9). The relationship between E-cad expression and clinicopathological features were investigated. In NGM, epithelial cells showed strong latero-lateral membranous expression of E-cad, and this pattern was considered normal. The membranous staining was preserved in all specimens of NNM (100%), whereas abnormal E-cad expression was found in 87.9% of the GCs. A marked difference in E-cad expression was observed between normal and malignant tissues (p < 0.0002). Abnormal E-cad expression was significantly more frequent in poorly/undifferentiated carcinomas (96%) and diffuse (95%) and indeterminate carcinomas (100%) than in well-differentiated/intestinal ones (62.5%; p = 0.0115 and p = 0.0392, respectively). There was significant association between abnormal E-cad expression and the depth of invasion (p = 0.0117), and the presence neoplastic emboli (p = 0.0194). No statistically significant differences in E-cad expression were observed concerning tumor location, histological type according to WHO classification, and presence of metastatic lesions. Therefore, deregulation of E-cad expression may play a role in canine gastric carcinogenesis and in tumor progression; moreover, it might be a prognostic tool for canine gastric cancer.

Gambogic acid inhibits epithelial–mesenchymal transition in breast cancer cells through upregulation of SIRT1 expression in vitro

AbstractGambogic acid (GA) is a natural product that selectively induces apoptosis of cancer cells in vitro with high efficiency and low toxicity. Our previous data have shown inhibitory effects of GA on breast cancer cells. However, the detailed mechanisms for GA remain largely unknown. This study aimed to investigate the effect of GA on TGF‐β1‐induced tumor invasion and EMT in MDA‐MB‐231 cells, and contribution of elevated SIRT1 to antitumor effects of GA. Human breast cell MDA‐MB‐231 and MDA‐MB‐231 were incubated with TGF‐β1 (100 ng/ml) and GA. Cell viability was determined by MTT assay, while tumor invasion was determined by Boyden chamber invasion assay. The mRNA levels of SIRT1 and TGF‐β1 were measured by quantitative real‐time polymerase chain reaction (qRT‐PCR). The protein expressions of SIRT1 and EMT‐associated mesenchymal marker Vimentin were measured by Western blotting. Interleukin‐6 (IL‐6) protein content was measured by enzyme linked immunosorbent assays (ELISAs). Our results showed that, GA showed decreased proliferation in MDA‐MB‐231 cells, especially in MDA‐MB‐231 cells with TGF‐β1 incubation. GA inhibited tumor invasion and EMT in TGF‐β1‐treated MDA‐MB‐231 cells. GA increased mRNA and protein expression of SIRT1 in MDA‐MB‐231 cells with and without TGF‐β1 treatment. SIRT1 mRNA level in MDA‐MB‐231 cells was increased by TGF‐β1 incubation and decreased by GA treatment. In addition, the production of IL‐6 was increased by TGF‐β1, and decreased by GA. In conclusion, GA inhibits tumor invasion and EMT in breast cancer, potentially through upregulating SIRT1 expression. This study provides a novel antitumor effect of GA in breast cancer.

Natural Plant Compounds: Does Caffeine, Dipotassium Glycyrrhizinate, Curcumin, and Euphol Play Roles as Antitumoral Compounds in Glioblastoma Cell Lines?

Many plant-derived compounds are shown to be promising antitumor therapeutic agents by enhancing apoptosis-related pathways and cell cycle impairment in tumor cells, including glioblastoma (GBM) cell lines. We aimed to review four natural plant compounds effective in GBM cell lines as caffeine, dipotassium glycyrrhizinate (DPG), curcumin, and euphol. Furthermore, antitumoral effect of these plant compounds on GBM cell lines through microRNAs (miRs) modulation was investigated. However, only DPG and curcumin were found as effective on miR modulation. Caffeine arrests GBM cell cycle in G0/G1 phase by cyclin-dependent kinases (CDK) complex inhibition and by decreasing BCL-2 and increasing FOXO1 expression levels causing greater apoptotic activity. Caffeine can also directly inhibit IP3R3, p38 phosphorylation, and rho-associated protein kinase (ROCK), decreasing cell invasion and migration capacity or indirectly by inhibiting the tissue inhibitor metalloproteinase-1 (TIMP-1) and integrins β1 and β3, leading to lower matrix metalloproteinases, MMP-2 and MMP-9. DPG presents antitumoral effect in GBM cells related to nuclear factor kappa B (NF-κB) pathway suppression by IRAK2 and TRAF6-mediating miR-16 and miR-146a, respectively. More recently, it was observed that DPG upregulated miR-4443 and miR-3620, responsible for post-transcriptional inhibition of the NF-κB pathway by CD209 and TNC modulation, respectively leading to lower MMP-9 and migration capacity. Curcumin is able to increase miR-223-3p, miR-133a-3p, miR-181a-5p, miR-34a-5p, miR-30c-5p, and miR-1290 expression leading to serine or threonine kinase (AKT) pathway impairment and also it decreases miR-27a-5p, miR-221-3p, miR-21-5p, miR-125b-5p, and miR-151-3p expression causing p53-BCL2 pathway inhibition and consequently, cellular apoptosis. Interestingly, lower expression of miR-27a by curcumin action enhanced the C/EBP homologous protein(CHOP) expression, leading to paraptosis. Curcumin can inhibit miR-21 expression and consequently activate apoptosis through caspase 3 and death receptor (DR) 4 and 5 activation. Autophagy is controlled by the LC-3 protein that interacts with Atg family for the LC3-II formation and autophagy activation. Euphol can enhance LC3-II levels directly in GBM cells or inhibits tumor invasion and migration through PDK1 modulation.

Controlled Fabrication of Bioactive Microtubes for Screening Anti-Tongue Squamous Cell Migration Drugs.

The treatment of tongue squamous cell carcinoma (TSCC) faces challenges because TSCC has an aggressive biological behavior and manifests usually as widespread metastatic disease. Therefore, it is particularly important to screen out and develop drugs that inhibit tumor invasion and metastasis. Two-dimensional (2D) cell culture has been used as in vitro models to study cellular biological behavior, but growing evidence now shows that the 2D systems can result in cell bioactivities that deviate appreciably the in vivo response. It is urgent to develop a novel 3D cell migration model in vitro to simulate the tumor microenvironment as much as possible and screen out effective anti-migration drugs. Sodium alginate, has a widely used cell encapsulation material, as significant advantages. We have designed a microfluidic device to fabricate a hollow alginate hydrogel microtube model. Based on the difference in liquid flow rate, TSCC cells (Cal27) were able to be evenly distributed in the hollow microtubes, which was confirmed though fluorescence microscope and laser scanning confocal microscope (LSCM). Our microfluidic device was cheap, and commercially available and could be assembled in a modular way, which are composed of a coaxial needle, silicone hose, and syringes. It was proved that the cells grow well in artificial microtubes with extracellular matrix (ECM) proteins by LSCM and flow cytometry. Periodic motility conferred a different motor state to the cells in the microtubes, more closely resembling the environment in vivo. The quantitative analysis of tumor cell migration could be achieved simply by determining the position of the cell in the microtube cross-section. We verified the anti-migration effects of three NSAIDs drugs (aspirin, indomethacin, and nimesulide) with artificial microtubes, obtaining the same results as conventional migration experiments. The results showed that among the three NSAIDs, nimesulide showed great anti-migration potential against TSCC cells. Our method holds great potential for application in the more efficient screening of anti-migration tumor drugs.

Targeted intelligent mesoporous polydopamine nanosystems for multimodal synergistic tumor treatment.

Developing intelligent responsive platforms to carry out high-performance therapy is of great interest for the treatment of tumors and their metastases. However, effective drug loading, activity maintenance, off-target leakage, and response to collaborative therapy remain great challenges. Herein, a targeted intelligent responsive mesoporous polydopamine (MPDA) nanosystem was reported for use in gene-mediated photochemotherapy for synergistic tumor treatment. First, the MPDA was surface modified to maintain a positive charge near the surface and to impart active targeting. Then, gambogic acid (GA) was encapsulated in the MPDA, solidified by phase change materials (PCMs), and finally loaded with siRNA by electrostatic interactions to obtain the smart nanodelivery system (PPMD@GA/si). In vitro and in vivo experiments showed that it not only effectively avoids siRNA inactivation and accidental release of GA, but also possesses potential for targeted accumulation to tumor tissue and mild-temperature photothermal therapy and chemotherapy via near infrared (NIR) radiation. Additionally, the release of siRNA could also effectively inhibit tumor invasion and metastasis to realize multimodal synergistic therapy. Overall, our studies provide a promising idea for synergistic tumor and metastasis treatment based on vector construction.

Molecular Mechanism of Inhibition of Polysialyltransferase Domain (PSTD) by Heparin.

The polysialic acid (polySia) is a unique carbohydrate polymer produced on the surface of Neuronal Cell Adhesion Molecule (NCAM) in a number of cancer cells, and strongly correlates with the migration and invasion of tumor cells and with aggressive, metastatic disease and poor clinical prognosis in the clinic. Its synthesis is catalyzed by two polysialyltransferases (polySTs), ST8SiaIV (PST) and ST8SiaII (STX). Selective inhibition of polySTs, therefore, presents a therapeutic opportunity to inhibit tumor invasion and metastasis due to NCAM polysialylation. It has been proposed that NCAM polysialylation could be inhibited by two types of heparin inhibitors, low molecular heparin (LMWH) and heparin tetrasaccharide (DP4). This review summarizes how the interactions between Polysialyltransferase Domain (PSTD) in ST8SiaIV and CMP-Sia, and between the PSTD and polySia take place, and how these interactions are inhibited by LMWH and DP4. Our NMR studies indicate that LMWH is a more effective inhibitor than DP4 for inhibition of NCAM polysialylation. The NMR identification of heparin-binding sites in the PSTD may provide insight into the design of specific inhibitors of polysialylation.

Abstract 2902: Beneficial effect of vactosertib combined with nal-IRI5-FU/LV in pancreatic cancer treatment

Abstract Pancreatic cancer is one of leading causes of cancer-related mortality in the world. Treatment of pancreatic cancer is difficult due to aggressiveness, distal metastasis, and genetic and epigenetic alterations. Especially, TGF-β is highly expressed in the pancreatic cancer patients, and it leads aggressive tumor metastasis. Regulation of TGF-β signaling is essential for controlling tumor progression and metastasis because TGF-β is involved in cell proliferation, epithelial-to-mesenchymal transition, angiogenesis, metastasis, and immune responses in cancer. Therefore, inhibition of TGF-β signaling may be the key concept of effective chemotherapies for metastatic pancreatic cancer. Recently, nanoliposomal iriotecan (nal-IRI), 5-flourouracil (5-FU) and leucovorin (LV) adjuvant therapy has been applied for pancreatic cancer patients' treatment. Vactosertib, one of the leading TGF-β inhibitor, has been used for clinical trials in many chemotherapy strategies. In this study, we investigated the combination treatment effect of nal-IRI/5-FU/LV and vactosertib on pancreatic cancer in syngeneic orthotopic pancreatic mouse model. The combination treatment significantly increased survival rate compare with control or single treatment of vactosertib or nal-IRI/5-FU/LV. In the histological analysis showed that cancer cell invasion to surrounding tissues was markedly reduced in vactosertib and combination treatment groups. In the RNA-sequencing analysis of tumor RNA, the apoptotic process are positively regulated in vactosertib plus nal-IRI/5-FU/LV group. Furthermore, we found the up-regulated differentially expressed gene (DEG), CCDC80, involved in cell migration, invasion and apoptosis. We ectopically overexpressed CCDC80 on pancreatic cancer cell lines and demonstrated the tumor suppressive role of CCDC80. In conclusion, the combination treatment with vactosertib with nal-IRI/5-FU/LV improved pancreatic cancer survival by inhibiting tumor invasion and inducing apoptosis. These results indicate that combination therapy can be applied to clinical trials in pancreatic cancer patient. This study supported by KHIDI grant (HI14C2640) and National R&amp;D Program for Cancer Control, Ministry for Health and Welfare, Republic of Korea (HA17C0037). Citation Format: Eunji Hong, Sujin Park, Akira Oshima, Jinsun Heo, Jinah Park, Jihee Lee, Kyoungwha Pang, Songee Han, Hyeyeon Park, Seong-Jin Kim. Beneficial effect of vactosertib combined with nal-IRI5-FU/LV in pancreatic cancer treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2902.

MiR‑29b suppresses proliferation and induces apoptosis of hepatocellular carcinoma ascites H22 cells viaregulating TGF‑β1 and p53 signaling pathway.

MicroRNA (miR)-29b is a key tumor regulator. It can inhibit tumor cell proliferation, induce apoptosis, suppress tumor invasion and migration, thus delaying tumor progression. Our previous studies revealed an increased level of miR-29b in hepatoma 22 (H22) cells in ascites tumor-bearing mice. The present study investigated the effect of miR-29b on proliferation and apoptosis of hepatocellular carcinoma ascites H22 cells and its association with the transforming growth factor-β1 (TGF-β1) signaling pathway and p53-mediated apoptotic pathway. Briefly, H22 cells were transfected with miR-29b-3p (hereinafter referred to as miR-29b) mimic or miR-29b inhibitor. MTS cell proliferation assay and flow cytometry were used to analyze cell viability and apoptosis. The expression change of the TGF-β1 signaling pathway and p53-mediated apoptotic pathway were detected by reverse transcription-quantitative PCR, western blotting and immunofluorescence. Furthermore, cells were treated with exogenous TGF-β1 and TGF-β1 small interfering RNA to evaluate the crosstalk between TGF-β1 and p53 under miR-29b regulation. The overexpression of miR-29b decreased cell viability, increased cell apoptosis, activated the TGF-β1 signaling pathway and p53-mediated apoptotic pathway. Conversely, these effects were reversed by the miR-29b inhibitor. Moreover, the effect of miR-29b mimic was further increased after treating cells with exogenous TGF-β1. The activation of the TGF-β1 signaling pathway and p53-mediated apoptotic pathway induced by miR-29b overexpression were reversed by TGF-β1 inhibition. In summary, these data indicated that miR-29b has an important role in proliferation and apoptosis of H22 cells by regulating the TGF-β1 signaling pathway, the p53-dependent apoptotic pathway, and the crosstalk between TGF-β1 and p53.

MiR‑135a‑5p inhibits tumor invasion by targeting ANGPT2 in gallbladder cancer

Gallbladder cancer (GBC) is the most aggressive cancer type in the biliary tract, and our previous studies observed that microRNA (miR)-135a-5p expression was downregulated in GBC tissues. However, few studies have focused on the mechanism of action of the miR-135a-5p target genes in GBC. The present study aimed to investigate the regulatory role of miR-135a-5p signaling in GBC. The present study found that miR-135a-5p expression was downregulated in GBC tissue, as detected by immunohistochemistry and reverse transcription-quantitative PCR. In addition, overexpression of miR-135a-5p significantly inhibited the proliferation and migration of GBC-SD cells. Using a luciferase activity assay, it was identified that angiopoietin-2 (ANGPT2) was a potential target gene of miR-135a-5p in GBC. Knockdown of ANGPT2 expression significantly inhibited the proliferation and invasion of GBC-SD cells. In conclusion, the present results suggested that miR-135a-5p affected GBC cell proliferation and invasion by targeting ANGPT2. Moreover, miR-135a-5p may be a potential biomarker for GBC progression and a potential target for GBC therapeutic intervention.

The Role of Tumor Microenvironment in Cancer Metastasis: Molecular Mechanisms and Therapeutic Opportunities.

Simple SummaryMetastasis, the process by which cancer cells escape primary tumor site and colonize distant organs, is responsible for most cancer-related deaths. The tumor microenvironment (TME), comprises different cell types, including immune cells and cancer-associated fibroblasts, as well as structural elements, such as collagen and hyaluronan that constitute the extracellular matrix (ECM). Intratumoral interactions between the cellular and structural components of the TME regulate the aggressiveness, and dissemination of malignant cells and promote immune evasion. At the secondary site, the TME also facilitates escape from dormancy to enhance metastatic tumor outgrowth. Moreover, the ECM applies mechanical forces on tumors that contribute to hypoxia and cancer cell invasiveness whereas also hinders drug delivery and efficacy in both primary and metastatic sites. In this review, we summarize the latest developments regarding the role of the TME in cancer progression and discuss ongoing efforts to remodel the TME to stop metastasis in its tracks.The tumor microenvironment (TME) regulates essential tumor survival and promotion functions. Interactions between the cellular and structural components of the TME allow cancer cells to become invasive and disseminate from the primary site to distant locations, through a complex and multistep metastatic cascade. Tumor-associated M2-type macrophages have growth-promoting and immunosuppressive functions; mesenchymal cells mass produce exosomes that increase the migratory ability of cancer cells; cancer associated fibroblasts (CAFs) reorganize the surrounding matrix creating migration-guiding tracks for cancer cells. In addition, the tumor extracellular matrix (ECM) exerts determinant roles in disease progression and cancer cell migration and regulates therapeutic responses. The hypoxic conditions generated at the primary tumor force cancer cells to genetically and/or epigenetically adapt in order to survive and metastasize. In the circulation, cancer cells encounter platelets, immune cells, and cytokines in the blood microenvironment that facilitate their survival and transit. This review discusses the roles of different cellular and structural tumor components in regulating the metastatic process, targeting approaches using small molecule inhibitors, nanoparticles, manipulated exosomes, and miRNAs to inhibit tumor invasion as well as current and future strategies to remodel the TME and enhance treatment efficacy to block the detrimental process of metastasis.

PTENε suppresses tumor metastasis through regulation of filopodia formation

PTEN is one of the most frequently mutated genes in malignancies and acts as a powerful tumor suppressor. Tumorigenesis is involved in multiple and complex processes including initiation, invasion, and metastasis. The complexity of PTEN function is partially attributed to PTEN family members such as PTENα and PTENβ. Here, we report the identification of PTENε (also named as PTEN5), a novel N‐terminal‐extended PTEN isoform that suppresses tumor invasion and metastasis. We show that the translation of PTENε/PTEN5 is initiated from the CUG816 codon within the 5′UTR region of PTEN mRNA. PTENε/PTEN5 mainly localizes in the cell membrane and physically associates with and dephosphorylates VASP and ACTR2, which govern filopodia formation and cell motility. We found that endogenous depletion of PTENε/PTEN5 promotes filopodia formation and enhances the metastasis capacity of tumor cells. Overall, we identify a new isoform of PTEN with distinct subcellular localization and molecular function compared to the known members of the PTEN family. These findings advance our current understanding of the importance and diversity of PTEN functions.