Selected aspects of avascular tumor growth reproduced by a hybrid model of cell dynamics and chemical kinetics

We here propose a hybrid computational framework to reproduce and analyze aspects of the avascular progression of a generic solid tumor. Our method first employs an individual-based approach to represent the population of tumor cells, which are distinguished in viable and necrotic agents. The active part of the disease is in turn differentiated according to a set of metabolic states. We then describe the spatio-temporal evolution of the concentration of oxygen and of tumor-secreted proteolytic enzymes using partial differential equations (PDEs). A differential equation finally governs the local degradation of the extracellular matrix (ECM) by the malignant mass. Numerical realizations of the model are run to reproduce tumor growth and invasion in a number scenarios that differ for cell properties (adhesiveness, duplication potential, proteolytic activity) and/or environmental conditions (level of tissue oxygenation and matrix density pattern). In particular, our simulations suggest that tumor aggressiveness, in terms of invasive depth and extension of necrotic tissue, can be reduced by (i) stable cell-cell contact interactions, (ii) poor tendency of malignant agents to chemotactically move upon oxygen gradients, and (iii) presence of an overdense matrix, if coupled by a disrupted proteolytic activity of the disease.

New insights into the role of thrombospondin-1 in glioblastoma development

Glioblastoma (GB), the most malignant subtype of diffuse glioma, is highly aggressive, invasive and vascularized. Its median survival is still short even with maximum standard care. There is a need to identify potential new molecules and mechanisms, that are involved in the interactions of GB cells with the tumor microenvironment (TME), for therapeutic intervention. Thrombospondin-1 (TSP1) is a multi-faceted matricellular protein which plays a significant role in development, physiology and pathology including cancer. Recent studies have pinpoint an important role of TSP1 in GB development which will be summarized and discussed herein. We will discuss studies, mainly from preclinical research, which should lead to a deeper understanding of TSP1's role in GB development. We will also discuss some issues with regard to the use of this knowledge for the clinic.

Metastatic effects of perfluorooctanoic acid (PFOA) on Drosophila melanogaster with metabolic reprogramming and dysrhythmia in a multigenerational exposure scenario

Perfluorooctanoic acid (PFOA) exposure correlated with various cancers and their mortality. Its persistence in the environment made its long-term multigenerational influences of significant concerns. However, it remained unanswered whether its multigenerational exposure could influence metastasis which contributes ~90 % to cancer mortality. In the present study, long-term effects of PFOA were measured in Drosophila melanogaster over 3 consecutive generations. In the morning-eclosed (AM) adult flies, PFOA significantly promoted tumor invasion rates and distances which increased over generations. Regarding metabolic reprogramming, PFOA disturbed the expressions of Glut1 and Pdk1, activities and contents of FASN1 (fatty acid synthase), ACC (acetyl-CoA carboxylase) and SREBP1 (sterol regulatory element binding protein). Regarding antioxidant responses, PFOA exposure generated provoked oxidative stress via H2O2 and stimulated antioxidants including glutathione (GSH), catalase (CAT), melatonin, serotonin and cortisol, with downregulations on PI3K/AKT pathways and upregulations on MAPK ones. The biochemical and molecular effects altered over generations. In the afternoon-eclosed (PM) adult flies, the metastasis of PFOA was more deteriorated than in AM adults. The significant influences of dysrhythmia were also observed in the multigenerational effects of PFOA on the metabolism reprogramming and antioxidant responses. The effects on rhythm-regulating gene expressions and protein levels explained the dysrhythmia and also indicated close interactions among metabolism reprogramming, antioxidant responses and rhythm regulation. ENVIRONMENTAL IMPLICATION: Numerous emerging per- and polyfluoroalkyl substances (PFASs) are being detected. Meanwhile, the toxicities of the emerging PFASs still depend on the progress of legacy PFASs for the continuity of scientific studies. As one legacy PFAS, perfluorooctanoic acid (PFOA) exposure correlated with various cancers and their mortality. Its persistence in the environment made its long-term multigenerational influences of significant concerns. However, it remained unanswered whether its multigenerational exposure could influence metastasis which contributes ~90 % to cancer mortality. The present study performed PFOA exposure for 3 consecutive generations. Results showed that the metastasis by PFOA increased over generations, and it was further deteriorated by dysrhythmia. Further analysis demonstrated the interactive involvement of metabolism reprogramming, antioxidant responses and rhythm regulation. The findings of the present study would highlight considerate points for studying the toxicities of emerging PFASs.

Hic-5 regulates extracellular matrix-associated gene expression and cytokine secretion in cancer associated fibroblasts

The focal adhesion protein, Hic-5 plays a key role in promoting extracellular matrix deposition and remodeling by cancer associated fibroblasts within the tumor stroma to promote breast tumor cell invasion. However, whether stromal matrix gene expression is regulated by Hic-5 is still unknown. Utilizing a constitutive Hic-5 knockout, Mouse Mammary Tumor Virus-Polyoma Middle T-Antigen spontaneous breast tumor mouse model, bulk RNAseq analysis was performed on cancer associated fibroblasts isolated from Hic-5 knockout mammary tumors. Functional network analysis highlighted a key role for Hic-5 in extracellular matrix organization, with both structural matrix genes, as well as matrix remodeling genes being differentially expressed in relation to Hic-5 expression. The subcellular distribution of the MRTF-A transcription factor and expression of a subset of MRTF-A responsive genes was also impacted by Hic-5 expression. Additionally, cytokine array analysis of conditioned media from the Hic-5 and Hic-5 knockout cancer associated fibroblasts revealed that Hic-5 is important for the secretion of several key factors that are associated with matrix remodeling, angiogenesis and immune evasion. Together, these data provide further evidence of a central role for Hic-5 expression in cancer associated fibroblasts in regulating the composition and organization of the tumor stroma microenvironment to promote breast tumor progression.

Tumor proliferation and invasion are intrinsically coupled and unraveled through tunable spheroid and physics-based models

Proliferation and invasion are two key drivers of tumor growth that are traditionally considered independent multicellular processes. However, these processes are intrinsically coupled through a maximum carrying capacity, i.e., the maximum spatial cell concentration supported by the tumor volume, total cell count, nutrient access, and mechanical properties of the tissue stroma. We explored this coupling of proliferation and invasion through in vitro and in silico methods where we modulated the mechanical properties of the tumor and the surrounding extracellular matrix. E-cadherin expression and stromal collagen concentration were manipulated in a tunable breast cancer spheroid to determine the overall impacts of these tumor variables on net tumor proliferation and continuum invasion. We integrated these results into a mixed-constitutive formulation to computationally delineate the influences of cellular and extracellular adhesion, stiffness, and mechanical properties of the extracellular matrix on net proliferation and continuum invasion. This framework integrates biological in vitro data into concise computational models of invasion and proliferation to provide more detailed physical insights into the coupling of these key tumor processes and tumor growth. STATEMENT OF SIGNIFICANCE: Tumor growth involves expansion into the collagen-rich stroma through intrinsic coupling of proliferation and invasion within the tumor continuum. These processes are regulated by a maximum carrying capacity that is determined by the total cell count, tumor volume, nutrient access, and mechanical properties of the surrounding stroma. The influences of biomechanical parameters (i.e., stiffness, cell elongation, net proliferation rate and cell-ECM friction) on tumor proliferation or invasion cannot be unraveled using experimental methods alone. By pairing a tunable spheroid system with computational modeling, we delineated the interdependencies of each system parameter on tumor proliferation and continuum invasion, and established a concise computational framework for studying tumor mechanobiology.

KCNA1 promotes the growth and invasion of glioblastoma cells through ferroptosis inhibition via upregulating SLC7A11

BACKGROUND

The high invasiveness and infiltrative nature of Glioblastoma (GBM) pose significant challenges for surgical removal. This study aimed to investigate the role of KCNA1 in GBM progression.

METHODS

CCK8, colony formation assay, scratch assay, transwell assay, and 3D tumor spheroid invasion assays were to determine how KCNA1 affects the growth and invasion of GBM cells. Subsequently, to confirm the impact of KCNA1 in ferroptosis, western blot, transmission electron microscopy and flow cytometry were conducted. To ascertain the impact of KCNA1 in vivo, patient-derived orthotopic xenograft models were established.

RESULTS

In functional assays, KCNA1 promotes the growth and invasion of GBM cells. Besides, KCNA1 can increase the expression of SLC7A11 and protect cells from ferroptosis. The vivo experiments demonstrated that knocking down KCNA1 inhibited the growth and infiltration of primary tumors in mice and extended survival time.

CONCLUSION

Therefore, our research suggests that KCNA1 may promote tumor growth and invasion by upregulating the expression of SLC7A11 and inhibiting ferroptosis, making it a promising therapeutic target for GBM.

The development of in vitro organotypic 3D vulvar models to study tumor-stroma interaction and drug efficacy

BACKGROUND

Vulvar squamous cell carcinoma (VSCC) is a rare disease with a poor prognosis. To date, there's no proper in vitro modeling system for VSCC to study its pathogenesis or for drug evaluation.

METHODS

We established healthy vulvar (HV)- and VSCC-like 3D full thickness models (FTMs) to observe the tumor-stroma interaction and their applicability for chemotherapeutic efficacy examination. VSCC-FTMs were developed by seeding VSCC tumor cell lines (A431 and HTB117) onto dermal matrices harboring two NF subtypes namely papillary fibroblasts (PFs) and reticular fibroblasts (RFs), or cancer-associated fibroblasts (CAFs) while HV-FTMs were constructed with primary keratinocytes and fibroblasts isolated from HV tissues.

RESULTS

HV-FTMs highly resembled HV tissues in terms of epidermal morphogenesis, basement membrane formation and collagen deposition. When the dermal compartment shifted from PFs to RFs or CAFs in VSCC-FTMs, tumor cells demonstrated more proliferation, EMT induction and stemness. In contrast to PFs, RFs started to lose their phenotype and express robust CAF-markers α-SMA and COL11A1 under tumor cell signaling induction, indicating a favored 'RF-to-CAF' transition in VSCC tumor microenvironment (TME). Additionally, chemotherapeutic treatment with carboplatin and paclitaxel resulted in a significant reduction in tumor-load and invasion in VSCC-FTMs.

CONCLUSION

We successfully developed in vitro 3D vulvar models mimicking both healthy and tumorous conditions which serve as a promising tool for vulvar drug screening programs. Moreover, healthy fibroblasts demonstrate heterogeneity in terms of CAF-activation in VSCC TME which brings insights in the future development of novel CAF-based therapeutic strategies in VSCC.

Suramin, a drug for the treatment of trypanosomiasis, reduces the prothrombotic and metastatic phenotypes of colorectal cancer cells by inhibiting hepsin

Recently, our group identified serine-protease hepsin from primary tumor as a biomarker of metastasis and thrombosis in patients with localized colorectal cancer. We described hepsin promotes invasion and thrombin generation of colorectal cancer cells in vitro and in vivo and identified venetoclax as a hepsin inhibitor that suppresses these effects. Now, we aspire to identify additional hepsin inhibitors, aiming to broaden the therapeutic choices for targeted intervention in colorectal cancer.

METHODS

We developed a virtual screening based on molecular docking between the hepsin active site and 2000 compounds from DrugBank. The most promising drug was validated in a hepsin activity assay. Subsequently, we measured the hepsin inhibitor effect on colorectal cancer cells with basal or overexpression of hepsin via wound-healing, gelatin matrix invasion, and plasma thrombin generation assays. Finally, a zebrafish model determined whether hepsin inhibition reduced the invasion of colorectal cancer cells overexpressing hepsin.

RESULTS

Suramin was the most potent hepsin inhibitor (docking score: -11.9691 Kcal/mol), with an IC50 of 0.66 µM. In Caco-2 cells with basal or overexpression of hepsin, suramin decreased migration and significantly reduced invasion and thrombin generation. Suramin did not reduce the thrombotic phenotype in the hepsin-negative colorectal cancer cells HCT-116 and DLD-1. Finally, suramin significantly reduced the in vivo invasion of Caco-2 cells overexpressing hepsin.

CONCLUSION

Suramin is a novel hepsin inhibitor that reduces its protumorigenic and prothrombotic effects in colorectal cancer cells. This suggests the possibility of repurposing suramin and its derivatives to augment the repertoire of molecular targeted therapies against colorectal cancer.

Fitting parameters and therapies of ODE tumor models with senescence and immune system

This work is devoted to introduce and study two quasispecies nonlinear ODE systems that model the behavior of tumor cell populations organized in different states. In the first model, replicative, senescent, extended lifespan, immortal and tumor cells are considered, while the second also includes immune cells. We fit the parameters regulating the transmission between states in order to approximate the outcomes of the models to a real progressive tumor invasion. After that, we study the identifiability of the fitted parameters, by using two sensitivity analysis methods. Then, we show that an adequate reduced fitting process (only accounting to the most identifiable parameters) gives similar results but saving computational cost. Three different therapies are introduced in the models to shrink (progressively in time) the tumor, while the replicative and senescent cells invade. Each therapy is identified to a dimensionless parameter. Then, we make a fitting process of the therapies' parameters, in various scenarios depending on the initial tumor according to the time when the therapies started. We conclude that, although the optimal combination of therapies depends on the size of initial tumor, the most efficient therapy is the reinforcement of the immune system. Finally, an identifiability analysis allows us to detect a limitation in the therapy outcomes. In fact, perturbing the optimal combination of therapies under an appropriate therapeutic vector produces virtually the same results.

The MRI appearance of myloglossus

PURPOSE

This case report describes the MRI appearance and significance of the myloglossus muscle, a variant extrinsic tongue muscle.

METHODS

The myloglossus muscle was incidentally discovered on imaging performed for head and neck cancer evaluation.

RESULTS

The myloglossus is best visualized on non-fat saturated T2 MRI and has signal characteristics that match those of muscle. It originates at the angle of the mandible and inserts into the tongue between the styloglossus and hyoglossus.

CONCLUSION

Accurate identification and delineation of the extrinsic muscles of the tongue, including the myloglossus, is essential for proper staging and treatment of head and neck cancers. This case report attempts to fill a void in depicting the MRI appearance of myloglossus muscle.

Tumor lesion detection in patients with cervical cancer by indocyanine green near-infrared imaging

PURPOSE

To investigate the feasibility and accuracy of near-infrared fluorescence (NIRF) imaging for detecting the extent of tumor invasion in cervical cancer using indocyanine green (ICG).

METHODS

We enrolled 51 patients who were diagnosed with cervical cancer with FIGO stage IB1-IIA2 disease. Patients were administered indocyanine green (ICG) at a dose of 5 mg/kg 24 h prior to surgery. A customized near-infrared fluorescence (NIRF) imaging system was used to identify the extent of tumor invasion when radical hysterectomy specimens were harvested. The relationship between tumor fluorescence intensity and clinicopathological characteristics was analyzed.

RESULTS

Of the 51 enrolled patients, 3 patients did not have residual tumors after cervical conization, and tumor lesions were identified by NIRF imaging in all the remaining 48 patients. The results of NIRF imaging were in agreement with the postoperative pathological findings in 95.8% of the patients with stromal invasion, 100% of those with surgical margin invasion, 100% of those with parametrial tumor involvement, and 100% of patients with uterine corpus invasion. The mean signal-to-background ratio (SBR) of the cervical tumors was 2.91 ± 1.64, and the SBR was independent of clinicopathological characteristics. Fluorescence microscopy confirmed that ICG fluorescence was present in the tumor nests.

CONCLUSIONS

NIRF imaging enables objective, accurate, and safe identification of tumor invasion during cervical cancer surgery.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT04224467.

Par6 Enhances Glioma Invasion by Activating MEK/ERK Pathway Through a LIN28/let-7d Positive Feedback Loop

The invasion of glioblastoma usually results in the recurrence and poor prognosis in patients with glioma. However, the underlying mechanisms involved in glioma invasion remains undefined. In this study, immunohistochemistry analyses of glioma specimens demonstrated that high expression of Par6 was positively correlated with malignancy and poor prognosis of patients with glioma. Par6-overexpressing glioma cells showed much more fibroblast-like morphology, suggesting that regulation of Par6 expression might be associated with tumor invasion in glioma cells. Further study indicated that Par6 overexpression subsequently increased CD44 and N-cadherin expression to enhance glioma invasion through activating MEK/ERK/STAT3 pathway, in vivo and in vitro. Moreover, we found that LIN28/let-7d axis was involved in this process via a positive feedback loop, suggesting that MEK/ERK/LIN28/let-7d/STAT3 cascade might be essential for Par6-mediated glioma invasion. Therefore, these data highlight the roles of Par6 in glioma invasion, and Par6 may serve as a potential therapeutic target for patients with glioma.

Metastatic effects of environmental carcinogens mediated by MAPK and UPR pathways with an in vivo Drosophila Model

Metastasis includes tumor invasion and migration and underlies over 90% of cancer mortality. The metastatic effects of environmental carcinogens raised serious health concerns. However, the underlying mechanisms remained poorly studied. In the present study, an in vivo Ras^V12/lgl^-/- model of the fruitfly, Drosophila melanogaster, with an 8-day exposure was employed to explore the metastatic effects of 3,3',4,4',5-pentachlorobiphenyl (PCB126), perfluorooctanoic acid (PFOA) and cadmium chloride (CdCl₂). At 1.0 mg/L, PCB126, PFOA, and CdCl₂ significantly increased tumor invasion rates by 1.32-, 1.33-, and 1.29-fold of the control, respectively. They also decreased the larval body weight and locomotion behavior. Moreover, they commonly disturbed the expression levels of target genes in MAPK and UPR pathways, and their metastatic effects were significantly abolished by the addition of p38 inhibitor (SB203580), JNK inhibitor (SP600125) and IRE1 inhibitor (KIRA6). Notably, the addition of the IRE inhibitor significantly influenced sna/E-cad pathway which is essential in both p38 and JNK regulations. The results demonstrated an essential role of sna/E-cad in connecting the effects of carcinogens on UPR and MAPK regulations and the resultant metastasis.

Prediction of nodal metastasis based on intraoral sonographic findings of the primary lesion in early-stage tongue cancer

The aim of this study was to clarify the correlation between imaging findings obtained using intraoral ultrasonography (US) and pathological findings of tongue cancers, and to examine the predictive value of intraoral US findings with respect to occult nodal metastasis. This was a retrospective study based on the medical records of 123 patients with T1-2N0 tongue cancer. The depth of invasion (DOI) on intraoral US was positively correlated with the pathological invasion depth (PID) (ρ = 0.7080, P < 0.0001). Receiver operating characteristic analyses revealed an optimal DOI cut-off value of 4.1 mm and optimal PID cut-off value of 3.9 mm to detect nodal metastasis. Regarding the margin shape of the primary tumour on intraoral US, the incidence of nodal metastasis was significantly higher for the permeated type than for the pressure type (P < 0.001) and wedge-shaped type (P = 0.002). Furthermore, tumours with peritumoural vascularity assessed by power Doppler US had a significantly higher incidence of nodal metastasis than tumours without (P = 0.003). The sensitivity, specificity, and accuracy of the permeated type to predict nodal metastasis was 53.6%, 95.8%, and 86.2%, respectively. These results suggest that intraoral US findings closely reflect pathological findings and could be useful to predict occult nodal metastasis in patients with early-stage tongue cancer.

Radiation modulates expression and related activities of c-Met protein in oral tongue squamous cell carcinoma cell lines

OBJECTIVES

c-Met, a receptor tyrosine kinase, is involved in the growth, invasion and metastasis of a variety of cancers. In a set of cell lines from several solid tumors, a five-fold increase in c-Met expression after irradiation has been reported. This study aimed to assess if c-Met is likewise abundantly expressed in oral tongue squamous cell carcinoma (OTSCC) upon exposure to irradiation, followed by a Met-induced biological response.

MATERIALS AND METHODS

Six OTSCC cell lines were exposed to gamma radiation doses of 2, 4, and 6 Gray. The changes in c-Met protein levels were assessed by western blot and flow cytometry. c-Met gene expression, cell migration, proliferation and cell cycle assays were performed as phenotypic readouts.

RESULTS

Irradiation resulted in upregulation of c.Met in all cell lines with different time kinetics. On average the cells displayed minimal c-Met expression on their surface ranging from 5 to 30% of total protein. Abrupt downregulation of c-Met surface expression occurred one hour after radiation but recovered 48 h post-radiation. Intracellularly, the highest level of expression was found on day 5 after radiation exposure. Irradiation induced aggressive invasive potential of the cells as determined in cell migration assays, particularly in cell lines with the highest c-Met expression.

CONCLUSIONS

These results provide novel insights into both intracellular and extracellular dynamics of c-Met expression profiles upon irradiation of OTSCC cells in vitro. It might also suggest that radiation enhances cell migration, indicative of invasiveness, through c-Met up-regulation, at least for certain types of OTSCC cells.

Diaph3 underlines tumor cell heterogeneity in glioblastoma with implications for treatment modalities resistance

INTRODUCTION

Glioblastoma (GBM) is the most aggressive central nervous system (CNS) tumor with astrocytic differentiation. The growth pattern of GBM mimics that of the precursor cell migration during the fetal development of the brain. Diaphanous homolog (Diaph3) has been established to play a role in both CNS maturation and cancer progression as it is required both for cell migration and division. Furthermore, Diaph3 has been shown to play a role in malignant disease progression through hyperactivation of the EGFR/MEK/ERK in loss of expression and its overexpression correlating to hyperactivity of the mTOR pathway, both of which are with a well-established role in GBM. Herein, we aimed at establishing the diagnostic role of Diaph3 immunohistochemistry expression patterns in GBM and their possible implications for molecular response to different therapies.

MATERIALS AND METHODS

The study utilized a retrospective nonclinical approach. Results of Diaph3 immunohistochemical expression were compared to healthy controls and reactive gliosis and statistically analyzed for correlation with neuroradiological tumor parameters and patient survival.

RESULTS

Healthy controls showed individual weakly positive cells, while reactive gliosis controls showed a strong expression in astrocytic projections. GBM samples showed a heterogeneous positive reaction to Diaph3, mean number of positive cells 62.66%, median 61.5, range 12-96%. Areas of migrating cells showed a strong diffuse cytoplasmic reaction. Cells located in the tumor core and those in areas of submeningeal aggregation had no antibody expression. Statistical analysis revealed no correlation with tumor size or patient survival.

CONCLUSION

The different expression pattern of Diaph3 in healthy controls, reactive gliosis and GBM shows promise as a clinical differentiating marker. Despite Diaph3 expression not correlating with survival and tumor size in GBM, there is an accumulating body of evidence that Diaph3 correlates with mTOR activity and can thus be used as a predictor for response to rapamycin and taxanes, clinical studies of which have shown promising, if mixed results in GBM.

Emerging roles of epithelial-mesenchymal plasticity in invasion-metastasis cascade and therapy resistance

Strong association of cancer incidence and its progression with mortality highlights the need to decipher the cellular and molecular mechanisms that drive tumor cells to rapidly progress to metastatic disease and therapy resistance. Epithelial-mesenchymal plasticity (EMP) emerged as a key regulator of metastatic outgrowth. It allows neoplastic epithelial cells to delaminate from their neighbors either individually or collectively, traverse the extracellular matrix (ECM) barrier, enter into the circulation, and establish distal metastases. Plasticity between epithelial and mesenchymal states and the existence of hybrid epithelial/mesenchymal (E/M) phenotypes are increasingly being reported in different tumor contexts. Small subset of cancer cells with stemness called cancer stem cells (CSCs) exhibit plasticity, possess high tumorigenic potential, and contribute to high degree of tumoral heterogeneity. EMP characterized by the presence of dynamic intermediate states is reported to be influenced by (epi)genomic reprograming, growth factor signaling, inflammation, and low oxygen generated by tumor stromal microenvironment. EMP alters the genotypic and phenotypic characteristics of tumor cells/CSCs, disrupts tissue homeostasis, induces the reprogramming of angiogenic and immune recognition functions, and renders tumor cells to survive hostile microenvironments and resist therapy. The present review summarizes the roles of EMP in tumor invasion and metastasis and provides an update on therapeutic strategies to target the metastatic and refractory cancers.

Modeling Collective Invasion and Single-Cell Mesenchymal Invasion in Three-Dimensional Matrigel-Collagen I Cultures

Understanding the modes and mechanisms of tumor cell invasion is key to developing targeted therapies against metastatic disease. In vitro assays modeling tumor progression have primarily been optimized for studying classical single-cell migration through an epithelial-mesenchymal transition (EMT). Although experimental and clinical histopathological evidence has revealed that tumor invasion is plastic and that epithelial carcinomas can invade by a range of modes that vary from single, mesenchyme-like cells, all the way to cohesive, collective units, few in vitro assays have been designed to assess these modes specifically. Thus, we have developed a Matrigel-Collagen I overlay assay that is suitable for identifying and quantifying both collective and mesenchymal invasion. This three-dimensional (3D) culture assay utilizes the features of Matrigel and Collagen I to mimic the laminin-rich basement membrane and the stiff, fibrillar Collagen I tumor microenvironment allowing for spheroid invasion to be assessed at the interface between these two matrix components.

Tumor invasion to the spinal region after primary surgery: A case report

Background

It is believed that pituitary carcinoma is a rare disorder and arise from the transformation of benign invasive macroadenomas, and the process of this transformation takes place slowly.

Case Presentation

A 51-year-old man presented with the clinical features of Cushing syndrome and walking impairment who was diagnosed with metastatic corticotroph pituitary carcinoma to the spine region, 6 years after the initial resection of a primary invasive pituitary adenoma. He made a visit to neurosurgery and endocrinology clinic with the chief complaint of weight gain, facial and extremities swelling, paresthesia, weakness, motion and speaking impairments, and HTN which all appeared through the last 1 year; hormonal laboratory tests showed urine free cortisol (UFC) 197.8 and 367. 30 ug/24hrs (36-137), cortisol 8 am after 1 mg overnight dexamethasone test 375 ng/mL (50-250) and ACTH 59 pg/mL. MRI study revealed a mass in the brainstem with the compression effect on spinal region, pituitary imagine does not differ from the last MRI. He underwent a neurosurgery for spinal mass resection, which was successful and the total mass was resected. After surgery, the patient's condition became better.

Conclusion

Pituitary carcinoma is a rare entity impossible to recognize as a primary tumor because its diagnosis by definition requires the presence of metastasis. Clinical awareness of the rare possibility for aggressive adenomas will progress, to metastasize is essential to appropriately monitor patients for possible early detection and treatment of pituitary carcinoma.

TRIM59 promotes osteosarcoma progression via activation of STAT3

Osteosarcoma (OS) is a common, highly malignant bone tumor. Tripartite motif-containing protein 59 (TRIM59) has been identified as a potential oncogenic protein involved in the initiation and progression of various human carcinomas. Nonetheless, the possible roles and molecular mechanisms of action of TRIM59 in OS remain unclear. In this study, we found that TRIM59 expression levels were frequently upregulated in OS tissues and cell lines. TRIM59 knockdown significantly suppressed the proliferation, migration, and invasion of OS cells and promoted OS cell apoptosis, whereas TRIM59 overexpression had the opposite effects. In vivo experiments demonstrated that TRIM59 knockdown suppressed OS tumor growth and metastasis in vivo. Furthermore, we found that TRIM59 directly interacted with phospho-STAT3 in OS cells. The downregulation of STAT3 levels attenuated TRIM59-induced cell proliferation and invasion. Taken together, our results indicate that TRIM59 promoted OS progression via STAT3 activation. Therefore, our study may provide a novel therapeutic target for OS.

Lactic acid in tumor invasion

Invasion involves tumor cells altering their cell-matrix interactions and acquiring motility for metastatic spread. Invasive tumor cells exhibit dysregulated metabolism and enhanced aerobic glycolysis, leading to nutrient depletion, hypoxia, and lactic acid production. Lactic acid is a byproduct of glycolysis capable of promoting oncogenic progression, but its role in tumor invasion is unclear. A growing number of studies have demonstrated that lactic acid regulates the degradation of collagen Ⅳ, collagen Ⅶ, and glycoprotein; the synthesis of collagen Ⅰ; and multiple signaling pathways, including TGF-β/Smad, Wnt/β-catenin, IL-6/STAT3, and HGF/MET, which are associated with basement membrane (BM) remodeling and epithelial-mesenchymal transition (EMT), two hallmarks of the tumor invasive process. In the present review, we summarize BM remodeling and EMT in tumor invasion, discuss the emerging roles and molecular mechanisms of lactic acid in these processes, and provide insights for further research.

PLD1 promotes tumor invasion by regulation of MMP-13 expression via NF-κB signaling in bladder cancer

Invasion of bladder cancer (BC) cells from the mucosa into the muscle layer is canonical for BC progression while phospholipase D isoform 1 (PLD1) is known to mediate development of cancer through phosphatidic acid (PA) production. We therefore used in silico, in vitro and in vivo approaches to detail the effect of PLD1 on BC invasion. In BC patients, higher levels of PLD1 expression were associated with poor prognoses. PLD1 knockdown significantly suppressed cellular invasion by human BC cells and matrix metalloproteinase-13 (MMP-13) was observed to mediate this effect. In our mouse bladder carcinogenesis model, the development of invasive BCs was suppressed by PLD1 knockout and a global transcriptomic analysis in this model indicated MMP-13 as a potential tumor invasion gene with NF-κB (nuclear factor-kB) as its transcriptional regulator. Furthermore, PA administration increased MMP-13 expression in line with NF-κB p65 phosphorylation levels. Collectively, we demonstrate that PLD1 promotes tumor invasion of BC by regulation of MMP-13 expression through the NF-κB signaling pathway and that PLD1 might be a potential therapeutic target to prevent clinical progression in BC patients.

Tumor budding in upper urinary tract urothelial carcinoma: a putative prognostic factor for extraurothelial recurrence and overall survival

Tumor budding, defined as a single cancer cell or clusters of fewer than five cancer cells observed at the tumor invasion front, has been reported to be associated with poor prognosis in various types of cancers. However, limited information regarding the pathological and prognostic significance of tumor budding in upper urinary tract urothelial carcinoma (UUTUC) is available. We investigated 135 consecutive patients with newly diagnosed invasive UUTUCs (73 with renal pelvic cancers and 62 with ureteral cancers) treated with nephroureterectomy or partial ureterectomy between 1999 and 2018 in our hospital. Under a × 200 magnification, tumors with 10 or more budding foci were defined as "high tumor budding". The median follow-up period was 53.6 months. Among the 135 patients, 41 (30%; 16 with renal pelvic cancers and 25 with ureteral cancers) showed high tumor budding. High tumor budding was related to adjuvant chemotherapy status, higher pathological T stage, lymphovascular invasion, lymph node metastasis, tumor location, concomitant variant histology, and non-papillary gross finding. The multivariate Cox analysis revealed that LVI and high tumor budding were independent predictors for extraurothelial recurrence (P = 0.039 and 0.014, hazard ratio = 2.50 and 2.88, respectively), and high tumor budding was an independent predictor for overall survival (P = 0.024, hazard ratio = 2.33). Tumor budding can be easily introduced in clinical practice with no need for immunohistochemical analysis, may be an important clinicopathological factor of UUTUC, and is suggested to be useful as a novel predictive prognostic factor of patients with invasive UUTUC.

Angiogenesis and vessel co-option in a mathematical model of diffusive tumor growth: The role of chemotaxis

This work considers the propagation of a tumor from the stage of a small avascular sphere in a host tissue and the progressive onset of a tumor neovasculature stimulated by a pro-angiogenic factor secreted by hypoxic cells. The way new vessels are formed involves cell sprouting from pre-existing vessels and following a trail via a chemotactic mechanism (CM). Namely, it is first proposed a detailed general family of models of the CM, based on a statistical mechanics approach. The key hypothesis is that the CM is composed by two components: i) the well-known bias induced by the angiogenic factor gradient; ii) the presence of stochastic changes of the velocity direction, thus giving rise to a diffusive component. Then, some further assumptions and simplifications are applied in order to derive a specific model to be used in the simulations. The tumor progression is favored by its acidic aggression towards the healthy cells. The model includes the evolution of many biological and chemical species. Numerical simulations show the onset of a traveling wave eventually replacing the host tissue with a fully vascularized tumor. The results of simulations agree with experimental measures of the vasculature density in tumors, even in the case of particularly hypoxic tumors.

Role of PD-L1 Expression during the Progression of Submucosal Gastric Cancer

INTRODUCTION

Programmed death-ligand 1 (PD-L1) expression is a prognostic marker for gastric cancer that correlates with tumor diameter and depth of penetration. But the role of PD-L1 and mechanism(s) employed in the initial phase of invasion in early gastric cancer is yet to be understood.

OBJECTIVE

This study aims to elucidate the role of PD-L1 during the progression of gastric cancer, specifically invading the submucosa beyond the lamina muscularis mucosa.

METHODS

Using 107 patients with pathological submucosal gastric cancer, we determined the expression of PD-L1 based on the staining of the cell membrane or cytoplasm of tumor cells in the central and invasive front of the tumor. Samples were categorized into 3 groups based on the intensity of PD-L1 expression. CD8+ lymphocytes expressing PD-1 and CD163+ macrophages were used to determine the number of cell nuclei at the invasive front, similar to PD-L1. CMTM6 levels were determined and used to stratify samples into 3 groups.

RESULTS

PD-L1 expression was higher in the invasive front (26.2%) than in the central portion of the tumors (7.4%; p < 0.001). Moreover, lymphatic and vascular invasion were more frequently observed in samples with high levels of PD-L1 (lymphatic invasion: 60.7 vs. 35.4%, p = 0.0026, and vascular invasion: 39.3 vs. 16.5%, p = 0.0018). There was no correlation between PD-L1 expression and the levels of PD-1, CD8, CD163, and CMTM6.

CONCLUSIONS

PD-L1-expressing cancer cells at the invasive front of gastric cancer influence the initial stages of tumor invasion and lymphovascular permeation in early-stage gastric cancers. Immune checkpoint signaling may be the driving force in the invasive front during the invasion of the submucosa beyond the lamina muscularis mucosa.

MMPs, tyrosine kinase signaling and extracellular matrix proteolysis in kidney cancer

Patients diagnosed with metastatic renal cell carcinoma (RCC) have ∼12% chance for 5-year survival. The integrity of the extracellular matrix (ECM) that surrounds tumor cells influences their behavior and, when disturbed, it could facilitate local invasion and spread of tumor cells to distant sites. The interplay between von Hippel-Lindau/hypoxia inducible factor signaling axis and activated kinase networks results in aberrant ECM and tumor progression. Matrix metalloproteinases (MMPs) are proteolytic enzymes implicated in ECM remodeling, tumor angiogenesis, and immune cell infiltration. Understanding the cross-talk between kinase signaling and ECM proteolysis in RCC could provide insights into developing drugs that interfere specifically with the process of invasion. In this review, we discuss changes in the MMPs/ECM axis in RCC, prominent kinase signaling pathways implicated in MMPs induction, and comment on emerging extracellular regulatory networks that modulate MMPs activity.

Effects of low extracellular sodium on proliferation and invasive activity of cancer cells in vitro

PURPOSE

Hyponatremia is the most common electrolyte disorder in hospitalized patients, and its etiopathogenesis is related to an underlying tumor in 14% of cases. Hyponatremia has been associated with a worse outcome in several pathologies, including cancer, in which the leading cause of this electrolyte alteration is the syndrome of inappropriate antidiuresis. The aim of this study was to analyze in vitro the effects of low extracellular [Na⁺] in cancer progression.

MATERIALS AND METHODS

We used a previously validated experimental model of chronic hyponatremia to characterize the effects of low extracellular [Na⁺] in different human cancer cell lines: pancreatic adenocarcinoma (PANC-1), neuroblastoma (SK-N-AS, SH-SY5Y), colorectal adenocarcinoma (HCT-8), chronic myeloid leukemia (K562).

RESULTS

Our results demonstrate a direct relationship between low [Na⁺], reduced cell adhesion and increased invasion and proliferation in all cell lines tested. Accordingly, the number of tumor colonies grown in soft agar and the expression of collagenases type IV (metalloproteinases 2 and 9) were markedly higher in cancer cells exposed to reduced extracellular [Na⁺]. Gene analysis showed an upregulation of molecular pathways involved in oxidative stress (heme oxygenase 1) and in proliferation and invasion (RhoA, ROCK-1, ROCK-2). The activation of RhoA/ROCK pathway was paralleled by a deregulation of the cytoskeleton-associated proteins, resulting in the promotion of actin cytoskeletal remodeling and cell invasion.

CONCLUSIONS

Overall, our data demonstrate for the first time that low [Na⁺] promotes cancer progression in vitro, thus suggesting that hyponatremia is not a simple bystander of disease severity in cancer.

iTRAQ-based quantitative proteomic analysis of the inhibition of cervical cancer cell invasion and migration by metformin

In recent years the anti-diabetic drug metformin has been shown to inhibit tumor growth, but the underlying mechanism is unclear. Our previous results showed that metformin can destroy the sponge effect of long-chain non-coding RNA MALAT1/miR-142-3p and inhibit the proliferation of cervical cancer cells. Metformin can inhibit the PI3K/Akt signaling pathway and synergizes with Nelfinavir to inhibit the proliferation and invasion of cervical cancer cells. In this study, we used iTRAQ-based proteomics, mass spectrometry-based targeted proteomics, immunoblotting, and bioinformatics to analyze the molecular mechanism by which metformin inhibits the proliferation and invasion of cervical cancer cells. We found that 53 proteins were differentially expressed in cervical cancer cells after metformin treatment, of which 20 were up-regulated and 33 were down-regulated. Bioinformatics analysis showed that the 53 differentially expressed proteins are negative regulators of receptor signaling that inhibit cell growth and are mainly enriched in cell growth and apoptosis signaling pathways. We performed PRM verification on 11 of the differentially expressed proteins and found that they were all associated with apoptosis. We also found that metformin up-regulated the expression of the tumor suppressor IGFBP7 to inhibit the proliferation and invasion of cervical cancer cells. Our results indicate that metformin mainly regulates the insulin signaling pathway and interferes with cell proliferation and apoptosis to inhibit proliferation and invasion of cervical cancer cells. These differentially expressed proteins may become new targets for the treatment of cervical cancer.

A nomogram predicting the recurrence of hepatocellular carcinoma in patients after laparoscopic hepatectomy

BACKGROUND

Patients with hepatocellular carcinoma (HCC) undergoing surgical resection still have a high 5-year recurrence rate (~ 60%). With the development of laparoscopic hepatectomy (LH), few studies have compared the efficacy between LH and traditional surgical approach on HCC. The objective of this study was to establish a nomogram to evaluate the risk of recurrence in HCC patients who underwent LH.

METHODS

The clinical data of 432 patients, pathologically diagnosed with HCC, underwent LH as initial treatment and had surgical margin > 1 cm were collected. The significance of their clinicopathological features to recurrence-free survival (RFS) was assessed, based on which a nomogram was constructed using a training cohort (n = 324) and was internally validated using a temporal validation cohort (n = 108).

RESULTS

Hepatitis B surface antigen (hazard ratio [HR], 1.838; P = 0.044), tumor number (HR, 1.774; P = 0.003), tumor thrombus (HR, 2.356; P = 0.003), cancer cell differentiation (HR, 0.745; P = 0.080), and microvascular tumor invasion (HR, 1.673; P  =0.007) were found to be independent risk factors for RFS in the training cohort, and were used for constructing the nomogram. The C-index for RFS prediction in the training cohort using the nomogram was 0.786, which was higher than that of the 8th edition of the American Joint Committee on Cancer TNM classification (C-index, 0.698) and the Barcelona Clinic Liver Cancer staging system (C-index, 0.632). A high consistency between the nomogram prediction and actual observation was also demonstrated by a calibration curve. An improved predictive benefit in RFS and higher threshold probability of the nomogram were determined by receiver operating characteristic curve analysis, which was also confirmed in the validation cohort compared to other systems.

CONCLUSIONS

We constructed and validated a nomogram able to quantify the risk of recurrence after initial LH for HCC patients, which can be clinically implemented in assisting the planification of individual postoperative surveillance protocols.

Upregulated METTL3 promotes metastasis of colorectal Cancer via miR-1246/SPRED2/MAPK signaling pathway

BACKGROUND

m6A modification has been proved to play an important role in many biological processes. METTL3 as the main methyltransferase for methylation process has been found to be upregulated in many cancers, including CRC. Here, we investigate m6A modification and the underlying mechanism of METTL3 in the development of CRC.

METHODS

The expression of METTL3 was detected in large clinical patient samples. To evaluate the function of METTL3 in vitro and in vivo, colony formation, CCK-8, cell migration and invasion assays were performed. To find out the downstream target of METTL3, GEO dataset was re-mined. We analyzed expression and metastasis-related miRNA by Pearson correlation, and miR-1246 was selected. Here, to identify the downstream target of miR-1246, Targetscan and miRWalk were used. RIP and luciferase reporter assay further confirmed SPRED2 as the direct target of miR-1246.

RESULTS

We found that upregulated METTL3 is responsible for abnormal m6A modification in CRC and correlates positively with tumor metastasis. The gain- and loss-of-function indicates that METTL3 promotes cell migration and invasion in vitro and in vivo. Additionally, we confirmed that METTL3 can methylate pri-miR-1246, which further promotes the maturation of pri-miR-1246. By using bioinformatics tools, anti-oncogene SPRED2 was identified as the downstream target of miR-1246, wherein downregulated SPRED2 further reverses the inhibition of the MAPK pathway.

CONCLUSIONS

The present study demonstrates that the METTL3/miR-1246/SPRED2 axis plays an important role in tumor metastasis and provides a new m6A modification pattern in CRC development.

CXCL12-regulated miR-370-3p functions as a tumor suppressor gene by targeting HMGA2 in nonfunctional pituitary adenomas

Silencing of noncoding genes within the imprinted DLK1-MEG3 locus is exclusive to human nonfunctional pituitary adenomas (NFPAs), but the exact mechanism is still unclear. This study was designed to demonstrate the impact of CXCL12 on the expression of miRNAs within this locus and phenotypic alterations of NFPAs. Human NFPA samples were collected for screening differentially expressed miRNAs by CXCL12. Target mRNAs of the miRNAs were predicted and verified in vitro. Tumor phenotypic alterations were also tested. Another 51 NFPA samples were enrolled to examine the correlation and clinical features. The expression of miR-370 was decreased by CXCL12 treatment in NFPAs. miR-370-3p was predicted and verified to target HMGA2 as a tumor suppressor gene. Overexpression of HMGA2 inhibited its antitumor function. miR-370-3p was downregulated and HMGA2 was upregulated significantly in High grade NFPAs. In conclusion, the CXCL12/miR-370-3p/HMGA2 signaling pathway is involved in tumor growth and invasiveness of NFPAs.

sE-cadherin is upregulated in serum of patients with renal cell carcinoma and promotes tumor cell dissemination in vitro

INTRODUCTION

Cadherin family proteins are involved in the tumorigenesis of several malignancies. However, their significance in renal cell carcinoma (RCC) has not been extensively investigated. The current study investigates the potential of several cadherins to perform as biomarkers for tumor detection and exert functional RCC activity.

METHODS

Pre- and postoperative concentrations of sE-cadherin, cadherin-6, N-cadherin, cadherin-11, cadherin-17, and cadherin-5 were measured in serum of patients undergoing surgery for RCC and correlated to clinical and histopathological parameters. Control serum was obtained from healthy volunteers. A498 and Caki-1 cells were incubated with sE-cadherin and assessed for cell growth, adhesion, and chemotaxis.

RESULTS

sE-cadherin was significantly upregulated in RCC patients, as compared to controls, and discriminated them with striking accuracy (area under the curve value 0.83). Serum levels remained stable several days after surgery. Treating A498 and Caki-1 cancer cells with various concentrations of sE-cadherin attenuated cell growth and adhesion, while chemotaxis was augmented.

CONCLUSIONS

sE-cadherin is overexpressed in serum of RCC patients and provides a functional cellular switch from sessility to aggressive dissemination. While sE-cadherin is not tumor-specific and thus inappropriate for population-based screening, further studies are warranted to investigate its role in monitoring RCC and employing it as a therapeutic target.

IFNγ inhibits fibroblast-leading tumor cell invasion through downregulating N-cadherin

Tumor metastasis accounts for most tumor-associated mortality and is closely related with stromal fibroblasts in the tumor microenvironment. It was reported that fibroblasts promoted tumor metastasis through directly leading tumor cell invasion; however, inflammatory microenvironment in the growing tumor may influence the outcome. Here, we found that the cytokine IFNγ, a key immune mediator secreted by T cells, could alter mouse lung tumor associated fibroblast-leading LLC tumor cell invasion in Matrigel. The motility of fibroblasts and adhesion with tumor cells were dramatically impaired upon IFNγ stimulation. We further found that IFNγ reduced the expression of N-cadherin on the surface of fibroblasts through upregulating SMAD7 and suppressing the downstream SMAD2 phosphorylation. N-cadherin was essential for fibroblast motility and adhesions with tumor cells. Moreover, fibroblasts could promote tumor progression and the deficiency of IFNγR signaling in fibroblasts reduced liver metastasis of LLC tumor in vivo. Collectively, our results demonstrate that IFNγ inhibits fibroblast-leading tumor cell invasion by inhibiting the motility of fibroblasts and their adhesion with tumor cells. The findings indicate that inflammatory cytokines in the tumor microenvironment may regulate the fibroblast-associated tumor metastasis.

The Impact of a Multivisceral Resection and Adjuvant Therapy in Locally Advanced Colon Cancer

BACKGROUND

Multivisceral resection for locally advanced colon cancer is mandatory to achieve complete tumor resection. We aimed to determine if local multivisceral resections (LMR) for pT4 and pT3 tumors impact perioperative and long-term oncological outcomes.

METHODS

All stage II or III colon cancer patients who had surgery between 2004 and 2014 were identified. We analyzed patients with non-multivisceral resections (NMR) for pT4 tumors vs. pT4-LMR. In addition, outcomes were compared to both NMR and LMR pT3 patients.

RESULTS

LMR was performed in 55 (29.7%) of all patients with pT4 tumors and in 48 (8.9%) of all patients with pT3 tumors. The most commonly involved areas of extension were the abdominal wall and the small intestine. Transverse colon cancer was correlated with LMR. Morbidity rates were comparable between NMR and LMR, with the exception of higher rates of blood transfusion and postoperative ileus. Over one third of all pT4-NMR patients developed recurrent disease, which was higher compared to all other groups. Subsequently, overall and disease-specific survival, as well as disease-free survival (DFS), was worse for pT4-NMR, even after adjustment for pTN-staging, adjuvant therapy, and R0 resection. Furthermore, when analyzing only curative resections, radial margin < 1 cm along with nodal disease was independent predictor for worse DFS. Long-term outcomes were comparable between pT4-LMR and pT3 patients.

CONCLUSIONS

Multivisceral resection for locally advanced colon cancer preserves long-term oncological outcomes without increased postoperative morbidity. Moreover, LMR in pT3 tumors does not contribute to postoperative morbidity. Our study underlines the feasibility and importance of performing LMR when locally advanced cancer is suspected.

Mammary fibroblasts remodel fibrillar collagen microstructure in a biomimetic nanocomposite hydrogel

Architecture and microstructure of type I collagen fibers constitute central regulators of tumor invasion with aligned fibers providing a route for migration of stromal and cancer cells. Several different aspects of fibrillar collagen, such as stiffness, density, thickness, and pore size, may regulate migration of cancer cells, but determining effects of any one parameter requires clear decoupling of physical properties of collagen networks. The objective of this work is to develop and apply an in vitro three-dimensional (3D) tumor-extra cellular matrix (ECM) model with tunable physical parameters to define how stromal fibroblasts modulate collagen microstructure to control migration of breast cancer cells. We incorporated two different types of polyhedral oligomeric silsesquioxane (POSS) nano-molecules into a collagen/alginate matrix to induce different mechanisms of gelling. The resultant biomimetic, nanocomposite hydrogels show different collagen fibrillar microstructures while maintaining constant overall matrix stiffness, density, and porosimetry. Spheroids of human mammary fibroblasts embedded in these 3D matrices remodel the collagen network to varying extents based on differences in underlying matrix microstructures. The remodeled collagen matrix shows oriented, thicker fibrillar tracks, facilitating invasion of tumor cells. By decoupling effects of matrix stiffness and architecture, our nanocomposite hydrogels serve as robust platforms to investigate how biophysical properties of tumor environments control key processes regulating tumor progression in breast cancer and other malignancies. STATEMENT OF SIGNIFICANCE: Our manuscript demonstrates a new type of nanocomposite hydrogel with two different gelling mechanisms, produced by incorporating two types of polyhedral oligomeric silsesquioxane (POSS) nano-molecules into a collagen/alginate matrix. The resultant biomimetic hydrogels show different fibrillar collagen microstructures while maintaining constant overall matrix stiffness, density, and porosimetry. These gels allow us to uncouple effects of matrix stiffness versus architecture on migration and invasion of breast cancer cells and stromal fibroblasts. Upon embedding spheroids of human mammary fibroblasts (HMFs) and dissociated 231 breast cancer cells, we showed that HMFs remodeled the collagen network to differing extents dependent on starting matrix microstructures in each hydrogel. The remodeled collagen matrix showed aligned collagen fibers perpendicular to the surface of a spheroid with migrating HMFs following these fibers as occurs in tumors in vivo. To our knowledge, this is the first study showing significant different fibrillar collagen microstructures with constant collagen density and gel stiffness. This study establishes a new type of nanocomposite 3D hydrogels for studies of biophysical and cellular interactions in engineered tumor environments.

Four-Dimensional Thoracic CT in Free-Breathing Children

In pediatric thoracic CT, respiratory motion is generally treated as a motion artifact degrading the image quality. Conversely, respiratory motion in the thorax can be used to answer important clinical questions, that cannot be assessed adequately via conventional static thoracic CT, by utilizing four-dimensional (4D) CT. However, clinical experiences of 4D thoracic CT are quite limited. In order to use 4D thoracic CT properly, imagers should understand imaging techniques, radiation dose optimization methods, and normal as well as typical abnormal imaging appearances. In this article, the imaging techniques of pediatric thoracic 4D CT are reviewed with an emphasis on radiation dose. In addition, several clinical applications of pediatric 4D thoracic CT are addressed in various thoracic functional abnormalities, including upper airway obstruction, tracheobronchomalacia, pulmonary air trapping, abnormal diaphragmatic motion, and tumor invasion. One may further explore the clinical usefulness of 4D thoracic CT in free-breathing children, which can enrich one's clinical practice.

[Mechanisms of the suppression of proliferation and invasion ability mediated by microRNA-147b in esophageal squamous cell carcinoma]

Objective: To explore the expression of microRNA(miR)-147b in esophageal squamous cell carcinoma (ESCC) and its regulatory roles in cell proliferation, cell cycle and invasion as well as its molecular mechanisms. Methods: Real-time quantitative PCR (qPCR) was used to investigate the expression of miR-147b in ESCC tissues and cells. Negative control (NC) and miR-147b inhibitor were transfected into ESCC EC1 and EC9706 cells, which were divided into two groups: NC group and miR-147b inhibitor group, and qPCR was employed to detect the miR-147 level and CCK-8. Flow cytometry and Transwell chamber were utilized to investigate the effects of miR-147b downregulation on cell proliferation, cell cycle and invasion in ESCC cells. Besides, target genes of miR-147b was confirmed by double luciferase reporter assay. Subsequently, qPCR and Western blot were used to examine the effects of miR-147b downregulation on NDUFA4 expression, and NDUFA4 expression and its correlation with miR-147b were investigated in ESCC tissues. Results: Relative level of miR-147b in ESCC tissues (3.03±0.27) and cells were markedly higher than that in para-carcinoma tissues (1.00±0.01) and normal esophageal epithelial cell, and the differences had statistical significance (P<0.01), and its high expression was closely associated with clinical staging, invasion depth, histological grading and lymph node metastasis(P<0.05). Importantly, clinical staging, lymph node metastasis and miR-147b may be an independent prognostic factor in ESCC. Moreover, miR-147b downregulation dramatically suppressed cell proliferation, arrested cell cycle in G0/G1 phase and reduced invasion ability in ESCC cells. Most importantly, NDUFA4 was a direct target gene of miR-147b, and miR-147b inhibitor evidently upregulated the expression of NDUFA4. Furthermore, NDUFA4 displayed low expression in ESCC tissues and its expression exhibited negative correlation with miR-147b expression. Conclusions: The downregulation of miR-147b expression significantly suppresses the proliferation and invasion abilities as well as alters cell cycle distribution in ESCC.

Tumor-Secreted Exosomal miR-222 Promotes Tumor Progression via Regulating P27 Expression and Re-Localization in Pancreatic Cancer

BACKGROUND/AIMS

MicroRNAs (miRNAs) or exosomes have recently been shown to play vital regulatory or communication roles in cancer biology. However, the roles and mechanisms of exosomal miRNAs in pancreatic ductal adenocarcinoma (PDAC) remain unknown. We aimed to investigate the detailed roles and mechanisms of tumor-generated exosomal miRNAs in progression of PDAC.

METHODS

miR-222 was identified by miRNA microarray studies in exosomes of PDAC cells, and further analyzed in plasma exosomes of PDAC patients. The regulatory mechanisms of miR-222 were explored by qRT-PCR, WB, dual-luciferase assays and immunofluorescence or confocal analysis. Other biological assays include transwell, xenograft models and so on.

RESULTS

miR-222 is significantly high in tumor exosomes or highly invasive PDAC cells. miR-222 could directly regulate p27 to promote cell invasion and proliferation. miR-222 could also activate AKT by inhibiting PPP2R2A expression, thus inducing p27 phosphorylation and cytoplasmic p27 expression to promote cell survival, invasion and metastasis. Expressions of miR-222 and p27 were significantly inversely correlated, and cytoplasmic p27, instead of nuclear p27, was associated with tumor malignancy. miR-222 could be transmitted between PDAC cells via exosome communication, and the exosomal miR-222 communication is functional. Plasma exosomal miR-222 in PDAC patients was high and significantly correlated to tumor size and TNM stage, and was an independent risk factor for PDAC patient survival.

CONCLUSION

Tumor-generated exosomes could promote invasion and proliferation of neighboring tumor cells via miR-222 transmission, the plasma exosomal miR-222 plays important roles and may be a useful prognostic maker in PDAC.

Leukocyte Cell-Derived Chemotaxin 2 Retards Non-Small Cell Lung Cancer Progression Through Antagonizing MET and EGFR Activities

BACKGROUND/AIMS

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) therapy is a clinical option for non-small cell lung cancer (NSCLC) harboring activating EGFR mutations or for cancer with wild-type (WT) EGFR when chemotherapy has failed. MET receptor activation or MET gene amplification was reported to be a major mechanism of acquired resistance to EGFR-TKI therapy in NSCLC cells. Leukocyte cell-derived chemotaxin 2 (LECT2) is a multifunctional cytokine that was shown to suppress metastasis of hepatocellular carcinoma via inhibiting MET activity. Until now, the biological function responsible for LECT2's action in human NSCLC remains unclear.

METHODS

LECT2-knockout (KO) mice and NOD/SCID/IL2rgnull (NSG) mice were respectively used to investigate the effects of LECT2 on the tumorigenicity and metastasis of murine (Lewis lung carcinoma, LLC) and human (HCC827) lung cancer cells. The effect of LECT2 on in vitro cell proliferation was evaluated, using MTS and colony formation assays. The effect of LECT2 on cell motility was evaluated using transwell migration and invasion assays. An enzyme-linked immunosorbent assay was performed to detect secreted LECT2 in plasma and media. Co-immunoprecipitation and Western blot assays were used to investigate the underlying mechanisms of LECT2 in NSCLC cells.

RESULTS

Compared to WT mice, mice with LECT2 deletion exhibited enhanced growth and metastasis of LLC cells, and survival times decreased in LLC-implanted mice. Overexpression of LECT2 in orthotopic human HCC827 xenografts in NSG mice resulted in significant inhibition of tumor growth and metastasis. In vitro, overexpression of LECT2 or treatment with a recombinant LECT2 protein impaired the colony-forming ability and motility of NSCLC cells (HCC827 and PC9) harboring high levels of activated EGFR and MET. Mechanistic investigations found that LECT2 bound to MET and EGFR to antagonize their activation and further suppress their common downstream pathways: phosphatidylinositol 3-kinase/Akt and extracellular signal-regulated kinase.

CONCLUSION

EGFR-MET signaling is critical for aggressive behaviors of NSCLC and is recognized as a therapeutic target for NSCLC especially for patients with acquired resistance to EGFR-TKI therapy. Our findings demonstrate, for the first time, that LECT2 functions as a suppressor of the progression of NSCLC by targeting EGFR-MET signaling.

Overexpression of Translocation Associated Membrane Protein 2 Leading to Cancer-Associated Matrix Metalloproteinase Activation as a Putative Metastatic Factor for Human Oral Cancer

Translocation associated membrane protein 2 (TRAM2) has been characterized as a component of the translocon that is a gated channel at the endoplasmic reticulum (ER) membrane. TRAM2 is expressed in a wide variety of human organs. To date, no information is available regarding TRAM2 function in the genesis of human cancer. The purpose of this study was to investigate the status of the TRAM2 gene in oral squamous cell carcinoma (OSCC) cells and clinical OSCC samples. Using real-time quantitative reverse transcriptase-polymerase chain reaction, Western blotting analysis, and immunohistochemistry, we detected accelerated TRAM2 mRNA and protein expression levels both in OSCC-derived cell lines and primary tumors. Moreover, TRAM2-positive OSCC tissues were correlated closely (P<0.05) with metastasis to regional lymph nodes and vascular invasiveness. Of note, knockdown of TRAM2 inhibited metastatic phenotypes, including siTRAM2 cellular migration, invasiveness, and transendothelial migration activities with a significant (P<0.05) decrease in protein kinase RNA(PKR) - like ER kinase (PERK) and matrix metalloproteinases (MMPs) (MT1-MMP, MMP2, and MMP9). Taken together, our results suggested that TRAM2 might play a pivotal role in OSCC cellular metastasis by controlling major MMPs. This molecule might be a putative therapeutic target for OSCC.

Hybrid collagen alginate hydrogel as a platform for 3D tumor spheroid invasion

Extracellular matrix regulates hallmark features of cancer through biochemical and mechanical signals, although mechanistic understanding of these processes remains limited by lack of models that recreate physiology of tumors. To tissue-engineer models that recapitulate three-dimensional architecture and signaling in tumors, there is a pressing need for new materials permitting flexible control of mechanical and biophysical features. We developed a hybrid hydrogel system composed of collagen and alginate to model tumor environments in breast cancer and other malignancies. Material properties of the hydrogel, including stiffness, microstructure and porosimetry, encompass parameters present in normal organs and tumors. The hydrogel possesses a well-organized, homogenous microstructure with adjustable mechanical stiffness and excellent permeability. Upon embedding multicellular tumor spheroids, we constructed a 3D tumor invasion model showing follow-the-leader migration with fibroblasts leading invasion of cancer cells similar to in vivo. We also demonstrated effects of CXCL12-CXCR4 signaling, a pathway implicated in tumor progression and metastasis, in a dual-tumor spheroid invasion model in 3D hydrogels. These studies establish a new hydrogel platform with material properties that can be tuned to investigate effects of environmental conditions on tumor progression, which will advance future studies of cancer cell invasion and response to therapy.

STATEMENT OF SIGNIFICANCE

Our manuscript describes a novel design of hybrid hydrogel system composed of collagen and alginate modeling 3D tumor environments in breast cancer. The hydrogel possesses a well-organized, homogenous microstructure with adjustable mechanical stiffness. Upon embedding tumor spheroids, we successfully showed a 3D tumor invasion model showing follow-the-leader migration with fibroblasts leading invasion of cancer cells similar to in vivo. To the best of our knowledge, this is the first study showing two spheroids invade simultaneously and forming bridge-like connection and effects of chemical gradients in 3D hydrogel environment. This research provides a new model for tumor-stromal interactions in cancer cell migration and establishes a novel hydrogel system for analyzing physical and biochemical signals regulating cancer progression and response to therapy.

Resveratrol interrupts the pro-invasive communication between cancer associated fibroblasts and cholangiocarcinoma cells

Cholangiocarcinoma (CCA), the cancer arising from the epithelial cells of bile ducts, is a prototype of inflammatory-driven cancer. Cytokines released by cancer associated fibroblasts (CAFs) play a pivotal role in CCA progression, driving the epigenetic Epithelial-to-Mesenchymal transition and the growth and metastasization of CCA cells. Consistently, the conditioned medium from CCA-derived CAFs further stimulated the secretion of IL-6, and to a lesser extent of IL-8, by CCA cells. CCA has a poor prognosis, because of late diagnosis and of high resistance to radio- and chemo-therapy of CCA cells. Targeting the CAFs and their secretion could be an alternative option. We found that while IL-6 indeed promoted the cell migration of invasive CCA cells, the nutraceutical Resveratrol strongly counteracted this effect both in CCA cells and in immortalized cholangiocytes. More importantly, here we show that Resveratrol has the potential to abrogate the secretion of IL-6 by CAFs. While the conditioned medium from CAFs strongly induced IL-6 mediated motility of CCA cells, the conditioned medium from CAFs pre-treated with Resveratrol completely halted cancer cell motility and reverted the N-to E-cadherin switch in migrating cells. This effect was associated with stimulation of autophagy in the cancer cells. This is the first demonstration that CAFs secretory products directly affect the regulation of autophagy and consequently the behavior of CCA cells, and that a nutraceutical may revert the malignant phenotype of cancer cells by acting on CAFs metabolism and secretion.

Expression profiles of TRPV1, TRPV4, TLR4 and ERK1/2 in the dorsal root ganglionic neurons of a cancer-induced neuropathy rat model

Background

The spread of tumors through neural routes is common in several types of cancer in which patients suffer from a moderate-to-severe neuropathy, neural damage and a distorted quality of life. Here we aim to examine the expression profiles of transient receptor potential vanilloid 1 (TRPV1) and of transient receptor potential vanilloid 4 (TRPV4), toll-like receptor 4 (TLR4) and extracellular signal-regulated kinase (ERK1/2), and to assess the possible therapeutic strategies through blockade of transient receptor potential (TRP) channels.

Methods

Cancer was induced within the sciatic nerves of male Copenhagen rats, and tissues from dorsal root ganglia (DRG) were collected and used for measurements of immunofluorescence and Western blotting. The TRPV1 antagonist capsazepine, the selective TRPV4 antagonist HC-067047 and the calcium ions inhibitor ruthenium red were used to treat thermal and/or mechanical hyperalgesia.

Results

Transient receptor potential vanilloid 1 showed a lower expression in DRGs on days 7 and 14. The expression of TRPV4, TLR4 and ERK1/2 showed an increase on day 3 then a decrease on days 7 and 14. TRPV1 and TLR4 as well as TRPV4 and ERK1/2 co-existed on the same neuronal cells. The neuropathic pain was reversed in dose-dependent manners by using the TRP antagonists and the calcium ions inhibitor.

Conclusion

The decreased expression of TRPV1 and TRPV4 is associated with high activation. The increased expression of TLR4 and ERK1/2 reveals earlier immune response and tumor progression, respectively, and their ultimate decrease is an indicator of nerve damage. We studied the possible role of TRPV1 and TRPV4 in transducing cancer-induced hyperalgesia. The possible treatment strategies of cancer-induced thermal and/or mechanical hyperalgesia using capsazepine, HC-067047 and ruthenium red are examined.

Knockdown of IFI27 inhibits cell proliferation and invasion in oral squamous cell carcinoma

Background

The development of oral squamous cell carcinoma (OSCC) involves genetic mutations, epigenetic gene expression modification, and other processes. It has been reported that IFI27 is upregulated in OSCC, but its function is unknown. The aim of this study was to investigate the role of IFI27 on OSCC cell proliferation and invasion.

Methods

The protein level of IFI27 in OSCC tissues and adjacent tissues was detected by immunohistochemistry. In the OSCC cell model, we designed the IFI27 siRNA to downregulate the expression of IFI27; gene and protein of IFI27 in those models were then detected by Q-PCR and Western blot. MTT assay was used to detect the effect of -IFI27 knockdown on cell proliferation; Annexin V-PI staining flow cytometry was used to detect the effect of IFI27 downregulation on apoptosis of cancer cells. The effect of IFI27 downregulation on oral cancer cell invasion was detected using Transwell assay.

Results

IFI27 was highly expressed in OSCC tissues by immunohistochemical assay. In the OSCC cell model, IFI27 siRNA could downregulate the mRNA and protein expression level of IFI27. As showed in MTT assay, Annexin V-PI assay, and Transwell assay, through the downregulation of IFI27, TSCCA and TCA8113 cell proliferation were inhibited, OSCC cell apoptosis was promoted, and its migration and invasion were inhibited.

Conclusion

IFI27 is involved in the development and progression of OSCC. Its high expression promotes cell proliferation and invasion and reduces apoptosis. These findings may provide new biomarkers and therapeutic targets for OSCC diagnosis and clinical treatment.

PHD-finger domain protein 5A functions as a novel oncoprotein in lung adenocarcinoma

BACKGROUND

PHD-finger domain protein 5A (PHF5A) is a highly conserved small transcriptional regulator also involved in pre-mRNA splicing; however, its biological functions and molecular mechanisms in non-small cell lung cancer (NSCLC) have not yet been investigated. The purpose of this study was to determine the functional relevance and therapeutic potential of PHF5A in lung adenocarcinoma (LAC).

METHODS

The expression of PHF5A in LAC tissues and adjacent non-tumor (ANT) tissues was investigated using immunohistochemistry of a tissue microarray, qRT-PCR, western blot and bioinformatics. The function of PHF5A was determined using several in vitro assays and also in vivo assay by lentiviral vector-mediated PHF5A depletion in LAC cell lines.

RESULTS

PHF5A was highly upregulated in LAC tissues compared with the ANT counterparts, and closely associated with tumor progression and poor patient prognosis. These results were further confirmed by findings of the TCGA database. Moreover, functional studies demonstrated that PHF5A knockdown not only resulted in reduced cell proliferation, increased cell apoptosis, and cell cycle arrest, but also suppressed migration and invasion in LAC cells. PHF5A silencing was also found to inhibit LAC tumor growth in nude mice. Microarray and bioinformatics analyses revealed that PHF5A depletion led to dysregulation of multiple tumor signaling pathways; selected factors in key signaling pathways were verified in vitro.

CONCLUSIONS

The data suggest for the first time that PHF5A is an oncoprotein that contributes to LAC progression by regulating multiple signaling pathways, and may constitute a prognostic factor and potential new therapeutic target in NSCLC.

Cancer-associated fibroblasts affect breast cancer cell gene expression, invasion and angiogenesis

PURPOSE

It has been reported that stromal cell features may affect the clinical outcome of breast cancer patients. Cancer associated fibroblasts (CAFs) represent one of the most abundant cell types within the breast cancer stroma. Here, we aimed to explore the influence of CAFs on breast cancer gene expression, as well as on invasion and angiogenesis.

METHODS

qRT-PCR was used to evaluate the expression of several cancer progression related genes (S100A4, TGFβ, FGF2, FGF7, PDGFA, PDGFB, VEGFA, IL-6, IL-8, uPA, MMP2, MMP9, MMP11 and TIMP1) in the human breast cancer-derived cell lines MCF-7 and MDA-MB-231, before and after co-culture with CAFs. Stromal mononuclear inflammatory cell (MIC) MMP11 expression was used to stratify primary tumors. In addition, we assessed the in vitro effects of CAFs on both MDA-MB-231 breast cancer cell invasion and endothelial cell (HUVEC) tube formation.

RESULTS

We found that the expression levels of most of the genes tested were significantly increased in both breast cancer-derived cell lines after co-culture with CAFs from either MMP11+ or MMP11- MIC tumors. IL-6 and IL-8 showed an increased expression in both cancer-derived cell lines after co-culture with CAFs from MMP11+ MIC tumors. We also found that the invasive and angiogenic capacities of, respectively, MDA-MB-231 and HUVEC cells were increased after co-culture with CAFs, especially those from MMP11+ MIC tumors.

CONCLUSIONS

Our data indicate that tumor-derived CAFs can induce up-regulation of genes involved in breast cancer progression. Our data additionally indicate that CAFs, especially those derived from MMP11+ MIC tumors, can promote breast cancer cell invasion and angiogenesis.

Cathepsin B inhibitors: Further exploration of the nitroxoline core

Human cathepsin B is a cysteine protease with many house-keeping functions, such as intracellular proteolysis within lysosomes. Its increased activity and expression have been strongly associated with many pathological processes, including cancers. We present here the design and synthesis of novel derivatives of nitroxoline as inhibitors of cathepsin B. These were prepared either by omitting the pyridine part, or by modifying positions 2, 7, and 8 of nitroxoline. All compounds were evaluated for their ability to inhibit endopeptidase and exopeptidase activities of cathepsin B. For the most promising inhibitors, the ability to reduce extracellular and intracellular collagen IV degradation was determined, followed by their evaluation in cell-based in vitro models of tumor invasion. The presented data show that we have further defined the structural requirements for cathepsin B inhibition by nitroxoline derivatives and provided additional knowledge that could lead to non-peptidic compounds with usefulness against tumor progression.

Role of matrix Metalloproteinases in pituitary adenoma invasion

Though pituitary adenomas are benign tumors in most cases, a considerable fraction of PAs behave in a malignant-like manner and invade to the adjacent structures in sellar region, especially the cavernous sinuses. Cancer-cell invasion and metastasis remain a great challenge for physicians and surgeons in spite of emerging advances in drug therapy and surgical Treatment. matrix metalloproteinases, as a family of zinc-dependent endopeptidases, have long been known to be associated with tumor invasion and metastasis mainly via breaking down basement membrane in different tissues. Aberrant expression and activation of matrix metalloproteinases have been detected in invasive pituitary adenomas as in malignancy and correlated to tumor invasion. Therefore, matrix metalloproteinases are considered as promising biomarkers for predicting tumor behavior and even drug targets for novel therapeutic strategies. In this review, we give an overview of the expression, function, regulation and clinical prospects of matrix metalloproteinases, especially focusing on the biological network in which matrix metalloproteinases may be abnormally activated in promoting pituitary adenoma invasion.

Ultrasound of the Normal Brachial Plexus

Ultrasound (US) allows a reliable examination of the brachial plexus except for the spinal nerve roots, located deep in the neuro-foramina, beyond the shadowing of the transverse processes of the vertebral bodies. All the other fascicles of the brachial plexus can be mapped by US from the roots of the spinal cervical nerves, from C5 to T1 to the branches at level of the axillary region. US can be considered as an alternative to Magnetic Resonance Imaging (MRI) when MRI is contraindicated, not readily available or in case of claustrophobia. US can be used for the assessment of the brachial plexus in case of trauma, tumours and fibrosis induced by radiation oncology treatments. US is also a valuable tool to perform imaging-guided blocks of the brachial plexus. A prerequisite for a reliable US examination of the brachial plexus is knowledge of its complex anatomy. The operator is also required to learn the appropriate US views in order to have an optimal depiction of the brachial plexus, especially the areas where the bone structure's interposition makes the visualisation of the brachial plexus more arduous. The aim of this review is to provide the reader with the basics principles of the US normal anatomy and technique for a reliable mapping of the brachial plexus.

TGF-β2 initiates autophagy via Smad and non-Smad pathway to promote glioma cells' invasion

Background

Glioblastoma multiforme (GBM) is characterized by lethal aggressiveness and patients with GBM are in urgent need for new therapeutic avenues to improve quality of life. Current studies on tumor invasion focused on roles of cytokines in tumor microenvironment and numerous evidence suggests that TGF-β2 is abundant in glioma microenvironment and vital for glioma invasion. Autopagy is also emerging as a critical factor in aggressive behaviors of cancer cells; however, the relationship between TGF-β2 and autophagy in glioma has been poorly understood.

Methods

U251, T98 and U87 GBM cell lines as well as GBM cells from a primary human specimen were used in vitro and in vivo to evaluate the effect of TGF-β2 on autophagy. Western blot, qPCR, immunofluorescence and transmission-electron microscope were used to detect target molecular expression. Lentivirus and siRNA vehicle were introduced to establish cell lines, as well as mitotracker and seahorse experiment to study the metabolic process in glioma. Preclinical therapeutic efficacy was evaluated in orthotopic xenograft mouse models.

Results

Here we demonstrated that TGF-β2 activated autophagy in human glioma cell lines and knockdown of Smad2 or inhibition of c-Jun NH2-terminal kinase, attenuated TGF-β2-induced autophagy. TGF-β2-induced autophagy is important for glioma invasion due to the alteration of epithelial-mesenchymal transition and metabolism conversion, particularly influencing mitochondria trafficking and membrane potential (△Ψm). Autopaghy also initiated a feedback on TGF-β2 in glioma by keeping its autocrine loop and affecting Smad2/3/7 expression. A xenograft model provided additional confirmation on combination of TGF-β inhibitor (Galunisertib) and autophagy inhibitor (CQ) to better “turn off” tumor growth.

Conclusion

Our findings elucidated a potential mechanism of autophagy-associated glioma invasion that TGF-β2 could initiate autophagy via Smad and non-Smad pathway to promote glioma cells’ invasion.

Electronic supplementary material

The online version of this article (10.1186/s13046-017-0628-8) contains supplementary material, which is available to authorized users.