Mesenchymal stem cells in lung cancer tumor microenvironment: their biological properties, influence on tumor growth and therapeutic implications

Computational modeling of multiple myeloma interactions with resident bone marrow cells

The interaction of multiple myeloma with bone marrow resident cells plays a key role in tumor progression and the development of drug resistance. The tumor cell response involves contact-mediated and paracrine interactions. The heterogeneity of myeloma cells and bone marrow cells makes it difficult to reproduce this environment in in-vitro experiments. The use of in-silico established tools can help to understand these complex problems. In this article, we present a computational model based on the finite element method to define the interactions of multiple myeloma cells with resident bone marrow cells. This model includes cell migration, which is controlled by stress-strain equilibrium, and cell processes such as proliferation, differentiation, and apoptosis. A series of computational experiments were performed to validate the proposed model. Cell proliferation by the growth factor IGF-1 is studied for different concentrations ranging from 0-10 ng/mL. Cell motility is studied for different concentrations of VEGF and fibronectin in the range of 0-100 ng/mL. Finally, cells were simulated under a combination of IGF-1 and VEGF stimuli whose concentrations are considered to be dependent on the cancer-associated fibroblasts in the extracellular matrix. Results show a good agreement with previous in-vitro results. Multiple myeloma growth and migration are shown to correlate linearly to the IGF-1 stimuli. These stimuli are coupled with the mechanical environment, which also improves cell growth. Moreover, cell migration depends on the fiber and VEGF concentration in the extracellular matrix. Finally, our computational model shows myeloma cells trigger mesenchymal stem cells to differentiate into cancer-associated fibroblasts, in a dose-dependent manner.

Predictive value of peritumour radiomics in the diagnosis of benign and malignant pulmonary nodules with halo sign

AIM

To evaluate peritumour radiomics in predicting benign and malignant pulmonary nodules with halo sign.

MATERIALS AND METHODS

In this retrospective study, 305 pulmonary nodules with halo sign (benign, 120; adenocarcinoma, 185) were collected. Manual segmentation was used to mark the gross tumour volume (GTV) and the peritumour volume (PTV) was established by uniform dilation (1 cm) of the tumour area in three dimensions. The GTV and PTV radiomic features were combined to produce the gross tumour and peritumour volume (GPTV). The minimum-redundancy maximum-relevance (mRMR) feature ranking method and least absolute shrinkage and selection operator (LASSO) algorithm were used to eliminate redundant radiomic features. Predictive models combined with clinical features and radiomic signatures were established. Multivarible logistic regression analysis was used to establish the combined model and develop a nomogram. Receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive performance of the model.

RESULTS

In the testing cohort, the area under the ROC curve (AUC) of the GTV, PTV, and GPTV radiomic models was 0.701 (95% CI: 0.589-0.814), 0.674 (95% CI: 0.557-0.791) and 0.755 (95% CI: 0.643-0.867), respectively. The AUC of the nomogram model based on clinical and GPTV radiomic signatures was 0.804 (95% CI: 0.707-0.901).

CONCLUSION

The nomogram model based on clinical and GPTV radiomic signatures can better predict benign and malignant pulmonary nodules with halo signs, demonstrating that the model has potential as a convenient and effective auxiliary diagnostic tool for radiologists.

Remote Adipose Tissue-Derived Stromal Cells of Patients with Lung Adenocarcinoma Generate a Similar Malignant Microenvironment of the Lung Stromal Counterpart

Cancer alters both local and distant tissue by influencing the microenvironment. In this regard, the interplay with the stromal fraction is considered critical as this latter can either foster or hamper the progression of the disease. Accordingly, the modality by which tumors may alter distant niches of stromal cells is still unclear, especially at early stages. In this short report, we attempt to better understand the biology of this cross-talk. In our "autologous stromal experimental setting," we found that remote adipose tissue-derived mesenchymal stem cells (mediastinal AMSC) obtained from patients with lung adenocarcinoma sustain proliferation and clonogenic ability of A549 and human primary lung adenocarcinoma cells similarly to the autologous stromal lung counterpart (LMSC). This effect is not observed in lung benign diseases such as the hamartochondroma. This finding was validated by conditioning benign AMSC with supernatants from LAC for up to 21 days. The new reconditioned media of the stromal fraction so obtained, was able to increase cell proliferation of A549 cells at 14 and 21 days similar to that derived from AMSC of patients with lung adenocarcinoma. The secretome generated by remote AMSC revealed overlapping to the corresponding malignant microenvironment of the autologous local LMSC. Among the plethora of 80 soluble factors analyzed by arrays, a small pool of 5 upregulated molecules including IL1-β, IL-3, MCP-1, TNF-α, and EGF, was commonly shared by both malignant-like autologous A- and L-MSC derived microenvironments vs those benign. The bioinformatics analysis revealed that these proteins were strictly and functionally interconnected to lung fibrosis and proinflammation and that miR-126, 101, 486, and let-7-g were their main targets. Accordingly, we found that in lung cancer tissues and blood samples from the same set of patients here employed, miR-126 and miR-486 displayed the highest expression levels in tissue and blood, respectively. When the miR-126-3p was silenced in A549 treated with AMSC-derived conditioned media from patients with lung adenocarcinoma, cell proliferation decreased compared to control media.

Hypoxia signaling in human health and diseases: implications and prospects for therapeutics

Molecular oxygen (O₂) is essential for most biological reactions in mammalian cells. When the intracellular oxygen content decreases, it is called hypoxia. The process of hypoxia is linked to several biological processes, including pathogenic microbe infection, metabolic adaptation, cancer, acute and chronic diseases, and other stress responses. The mechanism underlying cells respond to oxygen changes to mediate subsequent signal response is the central question during hypoxia. Hypoxia-inducible factors (HIFs) sense hypoxia to regulate the expressions of a series of downstream genes expression, which participate in multiple processes including cell metabolism, cell growth/death, cell proliferation, glycolysis, immune response, microbe infection, tumorigenesis, and metastasis. Importantly, hypoxia signaling also interacts with other cellular pathways, such as phosphoinositide 3-kinase (PI3K)-mammalian target of rapamycin (mTOR) signaling, nuclear factor kappa-B (NF-κB) pathway, extracellular signal-regulated kinases (ERK) signaling, and endoplasmic reticulum (ER) stress. This paper systematically reviews the mechanisms of hypoxia signaling activation, the control of HIF signaling, and the function of HIF signaling in human health and diseases. In addition, the therapeutic targets involved in HIF signaling to balance health and diseases are summarized and highlighted, which would provide novel strategies for the design and development of therapeutic drugs.

Mesenchymal stem cells: A living carrier for active tumor-targeted delivery

The strategy of using mesenchymal stem cells (MSCs) as a living carrier for active delivery of therapeutic agents targeting tumor sites has been attempted in a wide range of studies to validate the feasibility and efficacy for tumor treatment. This approach reveals powerful tumor targeting and tumor penetration. In addition, MSCs have been confirmed to actively participate in immunomodulation of the tumor microenvironment. Thus, MSCs are not inert delivery vehicles but have a strong impact on the fate of tumor cells. In this review, these active properties of MSCs are addressed to highlight the advantages and challenges of using MSCs for tumor-targeted delivery. In addition, some of the latest examples of using MSCs to carry a variety of anti-tumor agents for tumor-targeted therapy are summarized. Recent technologies to improve the performance and safety of this delivery strategy will be introduced. The advances, applications, and challenges summarized in this review will provide a general understanding of this promising strategy for actively delivering drugs to tumor tissues.

Lung Cancer and Granuloma Identification Using a Deep Learning Model to Extract 3-Dimensional Radiomics Features in CT Imaging

BACKGROUND

We aimed to evaluate a deep learning (DL) model combining perinodular and intranodular radiomics features and clinical features for preoperative differentiation of solitary granuloma nodules (GNs) from solid lung cancer nodules in patients with spiculation, lobulation, or pleural indentation on CT.

PATIENTS AND METHODS

We retrospectively recruited 915 patients with solitary solid pulmonary nodules and suspicious signs of malignancy. Data including clinical characteristics and subjective CT findings were obtained. A 3-dimensional U-Net-based DL model was used for tumor segmentation and extraction of 3-dimensional radiomics features. We used the Maximum Relevance and Minimum Redundancy (mRMR) algorithm and the eXtreme Gradient Boosting (XGBoost) algorithm to select the intranodular, perinodular, and gross nodular radiomics features. We propose a medical image DL (IDL) model, a clinical image DL (CIDL) model, a radiomics DL (RDL) model, and a clinical image radiomics DL (CIRDL) model to preoperatively differentiate GNs from solid lung cancer. Five-fold cross-validation was used to select and evaluate the models. The prediction performance of the models was evaluated using receiver operating characteristic and calibration curves.

RESULTS

The CIRDL model achieved the best performance in differentiating between GNs and solid lung cancer (area under the curve [AUC] = 0.9069), which was significantly higher compared with the IDL (AUC = 0.8322), CIDL (AUC = 0.8652), intra-RDL (AUC = 0.8583), peri-RDL (AUC = 0.8259), and gross-RDL (AUC = 0.8705) models.

CONCLUSION

The proposed CIRDL model is a noninvasive diagnostic tool to differentiate between granuloma nodules and solid lung cancer nodules and reduce the need for invasive diagnostic and surgical procedures.

Mesenchymal stem cells promote metastasis through activation of an ABL-MMP9 signaling axis in lung cancer cells

Mesenchymal stem cells (MSCs) are recruited and activated by solid tumors and play a role in tumor progression and metastasis. Here we show that MSCs promote metastasis in a panel of non-small cell lung cancer (NSCLC) cells. MSCs elicit transcriptional alterations in lung cancer cells leading to increased expression of factors implicated in the epithelial-to-mesenchymal transition (EMT) and secreted proteins including matrix metalloproteinase-9 (MMP9). MSCs enhance secretion of enzymatically active MMP9 in a panel of lung adenocarcinoma cells. High expression of MMP9 is linked to low survival rates in lung adenocarcinoma patients. Notably, we found that ABL tyrosine kinases are activated in MSC-primed lung cancer cells and functional ABL kinases are required for MSC-induced MMP9 expression, secretion and proteolytic activity. Importantly, ABL kinases are required for MSC-induced NSCLC metastasis. These data reveal an actionable target for inhibiting MSC-induced metastatic activity of lung adenocarcinoma cells through disruption of an ABL kinase-MMP9 signaling axis activated in MSC-primed lung cancer cells.

Modifying the tumour microenvironment and reverting tumour cells: New strategies for treating malignant tumours

The tumour microenvironment (TME) plays a pivotal role in tumour fate determination. The TME acts together with the genetic material of tumour cells to determine their initiation, metastasis and drug resistance. Stromal cells in the TME promote the growth and metastasis of tumour cells by secreting soluble molecules or exosomes. The abnormal microenvironment reduces immune surveillance and tumour killing. The TME causes low anti‐tumour drug penetration and reactivity and high drug resistance. Tumour angiogenesis and microenvironmental hypoxia limit the drug concentration within the TME and enhance the stemness of tumour cells. Therefore, modifying the TME to effectively attack tumour cells could represent a comprehensive and effective anti‐tumour strategy. Normal cells, such as stem cells and immune cells, can penetrate and disrupt the abnormal TME. Reconstruction of the TME with healthy cells is an exciting new direction for tumour treatment. We will elaborate on the mechanism of the TME to support tumours and the current cell therapies for targeting tumours and the TME—such as immune cell therapies, haematopoietic stem cell (HSC) transplantation therapies, mesenchymal stem cell (MSC) transfer and embryonic stem cell‐based microenvironment therapies—to provide novel ideas for producing breakthroughs in tumour therapy strategies.

CT-Imaging Based Analysis of Invasive Lung Adenocarcinoma Presenting as Ground Glass Nodules Using Peri- and Intra-nodular Radiomic Features

Objective: To evaluate whether radiomic features extracted from intra and peri-nodular lesions can enhance the ability to differentiate between invasive adenocarcinoma (IA), minimally invasive adenocarcinoma (MIA), and adenocarcinoma in situ (AIS) manifesting as ground-glass nodule (GGN). Materials and Methods: This retrospective study enrolled 120 patients with a total of 121 pathologically confirmed lung adenocarcinomas (85 IA and 36 AIS/MIA) from January 2015 to May 2019. The recruited patients were randomly divided into training (84 nodules) and validation sets (37 nodules), with a ratio of 7:3. The minority group in the training set was balanced by the synthetic minority over-sampling (SMOTE) method. The intra-, peri-nodular, and gross region of interests (ROI) were delineated with manual annotation. Image features were quantitatively extracted from each ROI on CT images. The minimum redundancy maximum relevance (mRMR) feature ranking method and the least absolute shrinkage and selection operator (LASSO) classifier were used to eliminate unnecessary features. The intra- and peri-nodular radiomic features were combined to produce the gross radiomic signature. A combined clinical-radiomic model was constructed by multivariable logistic regression analysis. The predicted performances of different models were evaluated using receiver operating curve (ROC) and calibration curve. Results: The gross radiomic signature (AUC: training set = 0.896; validation set = 0.876) showed a good ability to discriminate the invasiveness of adenocarcinoma, comparing to intra-nodular (AUC: training set = 0.862; validation set = 0.852) or peri-nodular radiomic signature (AUC: training set = 0.825; validation set = 0.820). The AUC of the combined clinical-radiomic model was 0.917 for the training and 0.876 for the validation cohort, respectively. Conclusions: The gross radiomic signature of intra- and peri-nodular regions improved the prediction ability and aided predicting the invasiveness of lung adenocarcinoma appearing as GGN.

Chemo-photodynamic therapy by pulmonary delivery of gefitinib nanoparticles and 5-aminolevulinic acid for treatment of primary lung cancer of rats

Lung cancer is a severe disease with high mortality. Chemotherapy is one major treatment for lung cancer. However, systemic chemotherapeutics usually distribute throughout the body without specific lung distribution so that serious side effects are unavoidable. Photodynamic therapy (PDT) is occasionally used for lung cancer treatment but photosensitizers are also systemically administered and the bronchoscopic intervention under anesthesia may hurt lung tissues. Here, we combined inhaled chemotherapeutics and photosensitizers for chemo-photodynamic therapy (CPDT) of primary lung cancer of rats with external laser light irradiation. Gefitinib PLGA nanoparticles (GNPs) were prepared. The anti-cancer effects of GNPs and/or a common photosensitizer 5-aminolevulinic acid (5-ALA) were explored on A549 cells (adenocarcinomic human alveolar basal epithelial cells) and primary lung cancer rats after intratracheal administration. External light irradiation was applied due to its higher safety compared to internal light irradiation that may result in injuries after a laser optic fiber was intubated into the lung. The remarkable synergistic effect of CPDT was confirmed although the single therapies were also effective, where the high anti-lung cancer effects were shown and some typical lung cancer markers, including CD31, VEGF, NF-κB p65 and Bcl-2, significantly decreased. Moreover, the treatments attenuated inflammation with the downregulation of TNF-α. The combination of pulmonary drug delivery and chemo-photodynamic therapy is a promising strategy for treatment of lung cancer.

Comparative study of intratracheal and oral gefitinib for the treatment of primary lung cancer

Oral gefitinib tablets are widely applied for the treatment of non-small cell lung cancer (NSCLC) though its broad distribution in the body may result in weak therapeutic efficiency and undesired side effects. Here, liposomal gefitinib dry powder inhalers (LGDs) were prepared using the injection-lyophilization method. LGDs were rough porous particles under a scanning electron microscope, which can be rapidly rehydrated to liposomes. LGDs and gefitinib powders were separately intratracheally (i.t.) administered into the lungs of primary lung cancer rats, while powdered gefitinib tablets were orally administered. Gefitinib was rapidly absorbed from the lung after i.t. administration of LGDs. The maximal gefitinib concentration in the circulation and the area under curve (AUC) of i.t. LGDs were higher than those of i.t. gefitinib powders and oral gefitinib. More importantly, much higher concentration and longer retention of gefitinib in the lung were shown after i.t. administration of LGDs and gefitinib powders but remarkably less drug distribution in the liver compared to oral gefitinib. LGDs showed higher therapeutic effect on rat primary lung cancer than i.t. gefitinib powders and oral gefitinib with reduction of inflammation, weak lung injury, and high apoptosis. Combination of inhalation and liposomes of anticancer drugs is a promising strategy for treatment of primary lung cancer.

Candida albicans Beta-Glucan Induce Anti- Cancer Activity of Mesenchymal Stem Cells against Lung Cancer Cell Line: An In-Vitro Experimental Study

OBJECTIVE

β-glucan, glucopyranosyl polymers of fungi cell wall, represent an immune stimulating effects with potential anti-cancer activity. Mesenchymal stem cells (MSC) have immunomodulating properties in cancer microenvironment. The aim of this study was to investigate the anti-cancer effect of Candida albicans (C. albicans) beta-glucan on MSCs supernatant for apoptosis assay of lung cancer cells in vitro.

METHODS

Beta-glucan was extracted from cell wall of C.albicans. MSC isolated from adipose tissue of patients and confirmed using specific surface markers expression which examined by flow cytometry. MSCs treated with various concentrations of β-glucans for 48 hours. Cytotoxic effect of β-glucans was evaluated using MTT assay. MSC and lung cancer line cocultured and treated with β-glucans and apoptosis assay was done by flow cytometry.

RESULTS

Cytotoxicity findings showed a significant decrease in MSC viability during 48h, however it was dose-dependent (P<0.05). According to the obtained findings, supernatant of mesenchymal stem cells treated with β-glucans increased cancer cells apoptosis (P<0.05).

CONCLUSION

Beta glucan may highlight a potential and novel promising candidate in future strategies to cause apoptosis of cancer cells and consider as therapeutic  agent against tumor growth as well. Definitely, more in vitro and in vivo studies are required to understand its functions.

Integrin α6 (CD49f), The Microenvironment and Cancer Stem Cells

Cancer is a highly prevalent and potentially terminal disease that affects millions of individuals worldwide. Here, we review the literature exploring the intricacies of stem cells bearing tumorigenic characteristics and collect evidence demonstrating the importance of integrin α6 (ITGA6, also known as CD49f) in cancer stem cell (CSC) activity. ITGA6 is commonly used to identify CSC populations in various tissues and plays an important role sustaining the self-renewal of CSCs by interconnecting them with the tumorigenic microenvironment.

Role of stanniocalcin-1 in breast cancer

Breast cancer is a highly heterogeneous disease consisting of five disease subtypes with distinct histological characteristics, clinical behaviors and prognostic features. Stanniocalcin-1 (STC1) is a secreted glycoprotein hormone that has been demonstrated to regulate calcium and phosphate homeostasis. Mammalian STC1 is expressed in various tissues and is implicated in multiple physiological and pathophysiological processes. In addition, growing evidence has suggested that STC1 serves an oncogenic role in a number of different types of tumor. However, the role of STC1 in breast cancer is complex, considering that some studies have shown that it exerts an oncogenic role, whereas other studies have demonstrated the opposite. The aim of the present review article is to evaluate the currently available data on mammalian STC1 and discuss its potential roles in each subtype of breast cancer.

Effects of mesenchymal stem cells harboring the Interferon-β gene on A549 lung cancer in nude mice

Interferon-β (IFN-β) exhibits a tumor-killing effect; however, injection of IFN-β alone for lung cancer is often accompanied by side effects. This study investigated the possibility of using umbilical cord mesenchymal stem cells (MSCs) as cellular carriers of IFN-β. Isolated umbilical cord MSCs were transfected with a lentivirus packaging IFN-β-overexpression plasmid. A549 cells were subcutaneously injected into nude mice to establish a non-small cell lung cancer (NSCLC) mouse model. A total of 50 mice were randomly assigned to 5 different groups: a control group, IFN-β group, IFN-β-MSCs group, MSCs-lentivirus group, and MSCs group. Next, the IFN-β-MSCs, MSCs-lentivirus, and MSCs were injected into the A549 lung cancer-bearing mice in the IFN-β-MSCs, MSCs-lentivirus and MSCs groups, respectively. Mice in the control and IFN-β groups were injected with solvent or IFN-β solution. The tumors in nude mice in the IFN-β and IFN-β-MSCs groups grew at significantly slower rates than tumors in the control group, and tumors in the MSCs-lentivirus and MSC groups also grew slowly. The rates of tumor cell apoptosis in the IFN-β and IFN-β-MSCs groups were significantly higher than those in the MSCs-lentivirus and MSCs groups. The livers, lungs, and kidneys of nude mice in the IFN-β group displayed hyperemia, exudation, and pathological lesions, while those of nude mice in the IFN-β-MSCs group showed no abnormal changes. Both INF-β-MSCs and INF-β inhibited the growth of subcutaneously implanted lung tumors; however, INF-β-MSCs specifically targeted the tumor cells, and did not produce the damage to internal organs caused by the use of INF-β alone.

Hypoxia inducible factor-1α/vascular endothelial growth factor signaling activation correlates with response to radiotherapy and its inhibition reduces hypoxia-induced angiogenesis in lung cancer

Like other tumors, lung cancer must induce angiogenesis as it grows. Hypoxia-inducible factor 1α (HIF-1α) is the inducible subunit of the HIF-1 transcription factor that regulates genes involved in the response to hypoxia, some of which contributes to angiogenesis. Vascular endothelial growth factor (VEGF) is one of the genes upregulated by HIF-1 and is the primary cytokine in relation to angiogenesis. In this study we tested whether aberrant activation of hypoxia inducible factor-1α/vascular endothelial growth factor (HIF-1α/VEGF) pathway correlates with response to radiotherapy and examined the response of lung cancer cells to hypoxia in vitro. We determined increased expressions of HIF-1α and VEGF-A in 76 cancerous tissues of responders (complete remission and partial remission). HIF-1α and VEGF-A were shown to be upregulated in lung cancer cells in response to hypoxia. The treatment with anti-HIF-1α siRNA prior to hypoxia exposure was shown to decrease HIF-1α and VEGF-A expressions and reduce hypoxia-induced angiogenesis, suggesting that HIF-1α expression resulted in increased VEGF-A expression and activation of HIF-1α/VEGF pathway was responsible for hypoxia-induced angiogenesis. In conclusion, we identified the relationship between HIF-1α/VEGF pathway and response to radiotherapy and its role in angiogenesis in lung cancer in vitro. HIF-1α/VEGF pathway as a target for antiangiogenic treatment strategies for this tumor requires further investigation.

Inhalation treatment of primary lung cancer using liposomal curcumin dry powder inhalers

Lung cancer is the leading cause of cancer-related deaths. Traditional chemotherapy causes serious toxicity due to the wide bodily distribution of these drugs. Curcumin is a potential anticancer agent but its low water solubility, poor bioavailability and rapid metabolism significantly limits clinical applications. Here we developed a liposomal curcumin dry powder inhaler (LCD) for inhalation treatment of primary lung cancer. LCDs were obtained from curcumin liposomes after freeze-drying. The LCDs had a mass mean aerodynamic diameter of 5.81 μm and a fine particle fraction of 46.71%, suitable for pulmonary delivery. The uptake of curcumin liposomes by human lung cancer A549 cells was markedly greater and faster than that of free curcumin. The high cytotoxicity on A549 cells and the low cytotoxicity of curcumin liposomes on normal human bronchial BEAS-2B epithelial cells yielded a high selection index partly due to increased cell apoptosis. Curcumin powders, LCDs and gemcitabine were directly sprayed into the lungs of rats with lung cancer through the trachea. LCDs showed higher anticancer effects than the other two medications with regard to pathology and the expression of many cancer-related markers including VEGF, malondialdehyde, TNF-α, caspase-3 and BCL-2. LCDs are a promising medication for inhalation treatment of lung cancer with high therapeutic efficiency.

Reciprocal modulation of mesenchymal stem cells and tumor cells promotes lung cancer metastasis

Metastasis is a multi-step process in which direct crosstalk between cancer cells and their microenvironment plays a key role. Here, we assessed the effect of paired tumor-associated and normal lung tissue mesenchymal stem cells (MSCs) on the growth and dissemination of primary human lung carcinoma cells isolated from the same patients. We show that the tumor microenvironment modulates MSC gene expression and identify a four-gene MSC signature that is functionally implicated in promoting metastasis. We also demonstrate that tumor-associated MSCs induce the expression of genes associated with an aggressive phenotype in primary lung cancer cells and selectively promote their dissemination rather than local growth. Our observations provide insight into mechanisms by which the stroma promotes lung cancer metastasis.

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Distinct gene expression profiles distinguish normal lung and tumor-associated MSCs.

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MSCs induce EMT- and hypoxia-related genes in primary tumor cells and promote their metastatic potential.

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A 4-gene T-MSC signature is involved in MSC-induced metastasis promotion.

The tumor microenvironment, which includes mesenchymal stem cells (MSCs) among many other stromal cell types, plays a fundamental role in cancer metastasis. Although MSCs are suggested to participate in tumor progression, most studies thus far have been performed on bone marrow-derived MSCs and cancer cell lines. Using primary human pulmonary MSCs and paired lung cancer cells, we show that tumor cells modulate MSCs to acquire properties, including a four-gene signature, which allow them to promote tumor dissemination. Our results provide insight into the mutual cancer cell-stromal cell modulation that drives tumor dissemination.

Notch signaling and non-small cell lung cancer

Lung cancer is the leading cause of cancer-associated mortality worldwide. Elucidation of the pathogenesis and biology of lung cancer is critical for the design of an effective treatment for patients. Non-small cell lung cancer (NSCLC) accounts for 80–85% of lung cancer cases. The abnormal expression of Notch signaling pathway members is a relatively frequent event in NSCLC. The Notch signaling pathway serves important roles in cell fate determination, proliferation, differentiation and apoptosis. Increasing evidence supports the association of Notch signaling dysregulation with various types of malignant tumor, including NSCLC. Several studies have demonstrated that members of the Notch signaling pathway may be potential biomarkers for predicting the progression and prognosis of patients with NSCLC. Furthermore, Notch signaling serves critical roles in the tumorigenesis and treatment resistance of NSCLC cells by promoting the proliferation or inhibiting the apoptosis of NSCLC cells. The present review provides a detailed summary of the roles of Notch signaling in NSCLC.

Clinicopathological and prognostic significance of regulatory T cells in patients with non-small cell lung cancer: A systematic review with meta-analysis

The prognostic and clinicopathological value of regulatory T cells (Tregs) infiltration in patients with non-small cell lung cancer (NSCLC) remains undetermined. A comprehensive literature search of electronic databases (up to December 2015) was conducted. Relationship between Tregs infiltration and clinicopathological features, recurrence-free survival (RFS) and overall survival (OS) was investigated by synthesizing the qualified data. A total of 1303 NSCLC patients from 11 studies were included. The pooled hazard ratio (HR) for survival showed that high Tregs infiltration had no effect on RFS (HR = 2.03, 95% CI: 0.61–3.44, P = 0.708) and OS (HR = 1.20, 95% CI: 0.58–1.62, P = 0.981). High FoxP3⁺ Tregs infiltration was significantly associated with poor OS in NSCLC (HR = 3.88, 95% CI: 2.45–5.40, P = 0.000). Test methods, ethnicity and types of specimens had no effect on predicting prognosis of Tregs infiltration. While high Tregs infiltration was significantly correlated with smoking status [odds ratios (ORs) = 1.54, 95% CI: 1.15–2.08; P = 0.004], none of other clinicopathological characteristics such as gender, histological type, lymph node metastasis status, tumor size, vascular invasion, lymphatic invasion and pleural invasion were associated with Tregs infiltration. The present study demonstrated that high FoxP3⁺ Tregs infiltration was significantly associated with poor prognosis in NSCLC and smoking status.

Health state dependent multiphoton induced autofluorescence in human 3D in vitro lung cancer model

Lung diseases pose the highest risk of death and lung cancer is a top killer among cancers with a mortality rate up to 70% within 1 year after diagnosis. Such a fast escalation of this cancer development makes early diagnosis and treatment a highly challenging task, and currently there are no effective tools to diagnose the disease at an early stage. The ability to discriminate between healthy and tumorous tissue has made autofluorescence bronchoscopy a promising tool for detection of lung cancer; however, specificity of this method remains insufficiently low. Here, we perform autofluorescence imaging of human lung cancer invading a human functional airway using an in vitro model of Non Small Cell Lung Cancer which combines a reconstituted human airway epithelium, human lung fibroblasts and lung adenocarcinoma cell lines, OncoCilAir™. By using two-photon laser induced autofluorescence microscopy combined with spectrally resolved imaging, we found that OncoCilAir™ provides tissue's health dependent autofluorescence similar as observed in lung tissue in patients. Moreover, we found spectral and intensity heterogeneity of autofluorescence at the edges of tumors. This metabolic related heterogeneity demonstrates ability of tumor to influence its microenvironment. Together, our result shows that OncoCilAir™ is a promising model for lung cancer research.

Bone Marrow Derived Mesenchymal Stem Cells Involve in the Lymphangiogenesis of Lung Cancer and Jinfukang Inhibits the Involvement In Vivo

Lymphangiogenesis plays an important role in cancer metastasis. Bone marrow-derived mesenchymal stem cells (BMMSCs) migrate to the site of tumorigenesis and in turn promote the metastasis. However, whether BMMSCs involve in the lymphangiogenesis of lung cancer is unclear. Jinfukang has clinically been used for the treatment of non small cell lung cancer (NSCLC) in China. In this study, to investigate the involvement of BMMSCs in lymphangiogenesis in lung cancer, and evaluate the inhibitory effect of Jinfukang on the lymphangiogenesis, chimeric mice were prepared by transplanting bone marrow from green fluorescent protein (GFP) transgenic mice (C57BL/6-EGFP) into irradiated C57BL/6 mice. Then, the chimeric mice were injected subcutaneously with freshly prepared Lewis lung carcinoma cell suspension to make lung tumor model, and the model mice were further orally administrated with Jinfukang once per day for 3 weeks. Four weeks after the bone marrow transplantation, GFP-positive cells primarily existed in bone marrow of acceptor mice, and three more weeks after, Lewis lung carcinoma cells formed a tumor mass in chimeric mice. Observation of GFP-positive cells revealed that BMMSCs transferred into the lung tumor. Immunofluorescent analyses of lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1), a lymphatic endothelium marker, demonstrated a part of lymphatic endothelial cells in lung cancer were derived from BMMSCs, and those lymphatic endothelial cells contributed to the lung tumor lymphangiogenesis. Furthermore, Jinfukang treatment resulted in a significant reduction of the average weight of the tumor mass in chimeric mice, and displayed a significant lower number of LYVE-1 positive cells. The present results suggest that BMMSCs transfer to tumor, differentiate into lymphatic endothelial cells, and involve in the lymphangiogenesis in lung cancer of mice. Jinfukang inhibits the lung tumor mass via suppression of the BMMSCs transformation and lung tumor lymphangiogenesis. Our findings might provide the potential for the cancer therapies.

Targeting Cancer Stem Cells-A Renewed Therapeutic Paradigm

Metastasis is often accompanied by radio- and chemotherapeutic resistance to anticancer treatments and is the major cause of death in cancer patients. Better understanding of how cancer cells circumvent therapeutic insults and how disseminated cancer clones generate life-threatening metastases would therefore be paramount to the development of effective therapeutic approaches for clinical management of malignant disease. Mounting reports over the past two decades have provided evidence for the existence of a minor population of highly malignant cells within liquid and solid tumors, which are capable of self-renewing and of regenerating secondary growths with the heterogeneity of the primary tumors from which they derive. These cells, called tumor-initiating cells or cancer stem cells (CSCs) exhibit increased resistance to standard radio- and chemotherapies and appear to have mechanisms that enable them to evade immune surveillance. CSCs are therefore considered to be responsible for systemic residual disease after cancer therapy, as well as for disease relapse. How CSCs develop, the nature of the interactions they establish with their microenvironment, their phenotypic and functional characteristics, as well as their molecular dependencies have all taken center stage in cancer therapy. Indeed, improved understanding of CSC biology is critical to the development of important CSC-based anti-neoplastic approaches that have the potential to radically improve cancer management. Here, we summarize some of the most pertinent elements regarding CSC development and properties, and highlight some of the clinical modalities in current development as anti-CSC therapeutics.

Mesenchymal stem cells derived from normal gingival tissue inhibit the proliferation of oral cancer cells in vitro and in vivo

The interplay between tumor cells and mesenchymal stem cells (MSCs) within tumor microenvironment plays a significant role in tumor development, and thus might be exploited for therapeutic intervention. In this study, we isolated MSCs from normal gingival tissue (GMSCs), and detected the effect of GMSCs on oral cancer cells via direct co-culture and indirect co-culture systems. The cell proliferation assay of direct co-culture showed that GMSCs could inhibit the growth of oral cancer cells. Conditioned medium derived from GMSCs (GMSCs-CM) also exerted an anticancer effect, which indicates that soluble factors in GMSCs-CM played a dominant role in GMSCs-induced cancer cell growth inhibition. To investigate the mechanism, we performed apoptosis assay by flow cytometry, and confirmed that cancer cell apoptosis induced by GMSCs could be a reason for the effect of GMSCs on the growth of oral cancer cells. Western blotting also confirmed that GMSCs could upregulate expression of pro-apoptotic genes including p-JNK, cleaved PARP, cleaved caspase-3, Bax expression and downregulate proliferation- and anti-apoptosis-related gene expression such as p-ERK1/2, Bcl-2, CDK4, cyclin D1, PCNA and survivin. Importantly, the inhibitory effect of GMSCs on cancer cells can partially be restored by blockade of JNK pathway. Moreover, animal studies showed that GMSCs exerted an anticancer effect after oral cancer cells and GMSCs were co-injected with oral cancer cells. Taken together, our data suggest that GMSCs can suppress oral cancer cell growth in vitro and in vivo via altering the surrounding microenvironment of oral cancer cells, which indicates that GMSCs have a potential use in the management of oral dysplasia and oral cancer in future.

Dual targeting and enhanced cytotoxicity to HER2-overexpressing tumors by immunoapoptotin-armored mesenchymal stem cells

Mesenchymal stem cells (MSCs) are promising vehicles for the delivery of anticancer agents in cancer therapy. However, the tumor targeting of loaded therapeutics is essential. Here, we explored a dual-targeting strategy to incorporate tumor-tropic MSC delivery with HER2-specific killing by the immunoapoptotin e23sFv-Fdt-tBid generated in our previous studies. The MSC engineering allowed simultaneous immunoapoptotin secretion and bioluminescence detection of the modified MSCs. Systemic administration of the immunoapoptotin-engineered MSCs was investigated in human HER2-reconstituted syngeneic mouse models of orthotopic and metastatic breast cancer, as well as in a xenograft nude mouse model of orthotopic gastric cancer. In vivo dual tumor targeting was confirmed by local accumulation of the bioluminescence-imaged MSCs and persistence of His-immunostained immunoapoptotins in tumor sites. The added tumor preference of MSC-secreted immunoapoptotins resulted in a significantly stronger antitumor effect compared with purified immunoapoptotins and Jurkat-delivered immunoapoptotins. This immunoapoptotin-armored MSC strategy provides a rationale for its use in extended malignancies by combining MSC mobility with redirected immunoapoptotins against a given tumor antigen.

Wharton's jelly mesenchymal stromal cells have contrasting effects on proliferation and phenotype of cancer stem cells from different subtypes of lung cancer

Studies on the role of multipotent mesenchymal stromal cells (MSC) on tumor growth have reported both a tumor promoting and a suppressive effect. The aim of the present study was to determine the effect of MSC isolated from Wharton's jelly of umbilical cord (WJMSC) on lung cancer stem cells (LCSC) derived from human lung tumors: two adenocarcinomas (AC) and two squamous cell carcinomas (SCC). LCSC derived from SCC and AC expressed, to varying extents, the more relevant stem cell markers. The effect of WJMSC on LCSC was investigated in vitro using conditioned medium (WJ-CM): a proliferation increase in AC-LCSC was observed, with an increase in the ALDH+ and in the CD133+ cell population. By contrast, WJ-CM hampered the growth of SCC-LCSC, with an increase in the pre-G1 phase indicating the induction of apoptosis. Furthermore, the ALDH+ and CD133+ population was also reduced. In vivo, subcutaneous co-transplantation of AC-LCSC/WJMSC generated larger tumors than AC-LCSC alone, characterized by an increased percentage of CD133+ and CD166+ cells. By contrast, co-transplantation of WJMSC and SCC-LCSC did not affect the tumor size. Our results strongly suggest that WJMSC exert, both in vitro and in vivo, contrasting effects on LCSC derived from different lung tumor subtypes.

Effect of Irradiation on Tumor Microenvironment and Bone Marrow Cell Migration in a Preclinical Tumor Model

PURPOSE

To characterize the tumor microenvironment after standard radiation therapy (SRT) and pulsed radiation therapy (PRT) in Lewis lung carcinoma (LLC) allografts.

METHODS AND MATERIALS

Subcutaneous LLC tumors were established in C57BL/6 mice. Standard RT or PRT was given at 2 Gy/d for a total dose of 20 Gy using a 5 days on, 2 days off schedule to mimic clinical delivery. Radiation-induced tumor microenvironment changes were examined after treatment using flow cytometry and antibody-specific histopathology. Normal tissue effects were measured using noninvasive (18)F-fluorodeoxyglucose positron emission tomography/computed tomography after naïve animals were given whole-lung irradiation to 40 Gy in 4 weeks using the same 2-Gy/d regimens.

RESULTS

Over the 2 weeks of therapy, PRT was more effective than SRT at reducing tumor growth rate (0.31 ± 0.02 mm(3)/d and 0.55 ± 0.04 mm(3)/d, respectively; P<.007). Histopathology showed a significant comparative reduction in the levels of Ki-67 (14.5% ± 3%), hypoxia (10% ± 3.5%), vascular endothelial growth factor (2.3% ± 1%), and stromal-derived factor-1α (2.5% ± 1.4%), as well as a concomitant decrease in CD45(+) bone marrow-derived cell (BMDC) migration (7.8% ± 2.2%) after PRT. The addition of AMD3100 also decreased CD45(+) BMDC migration in treated tumors (0.6% ± 0.1%). Higher vessel density was observed in treated tumors. No differences were observed in normal lung tissue after PRT or SRT.

CONCLUSIONS

Pulsed RT-treated tumors exhibited slower growth and reduced hypoxia. Pulsed RT eliminated initiation of supportive mechanisms utilized by tumors in low oxygen microenvironments, including angiogenesis and recruitment of BMDCs.

Nanoparticles and mesenchymal stem cells: a win-win alliance for anticancer drug delivery

Schematic illustration of the combination of NPs and MSCs drug delivery systems for cancer therapy.

Mesenchymal Stem/Stromal Cells in Stromal Evolution and Cancer Progression

The study of cancer biology has mainly focused on malignant epithelial cancer cells, although tumors also contain a stromal compartment, which is composed of stem cells, tumor-associated fibroblasts (TAFs), endothelial cells, immune cells, adipocytes, cytokines, and various types of macromolecules comprising the extracellular matrix (ECM). The tumor stroma develops gradually in response to the needs of epithelial cancer cells during malignant progression initiating from increased local vascular permeability and ending to remodeling of desmoplastic loosely vascularized stromal ECM. The constant bidirectional interaction of epithelial cancer cells with the surrounding microenvironment allows damaged stromal cell usage as a source of nutrients for cancer cells, maintains the stroma renewal thus resembling a wound that does not heal, and affects the characteristics of tumor mesenchymal stem/stromal cells (MSCs). Although MSCs have been shown to coordinate tumor cell growth, dormancy, migration, invasion, metastasis, and drug resistance, recently they have been successfully used in treatment of hematopoietic malignancies to enhance the effect of total body irradiation-hematopoietic stem cell transplantation therapy. Hence, targeting the stromal elements in combination with conventional chemotherapeutics and usage of MSCs to attenuate graft-versus-host disease may offer new strategies to overcome cancer treatment failure and relapse of the disease.

Secretome of human bone marrow mesenchymal stem cells: an emerging player in lung cancer progression and mechanisms of translation initiation

Non-small cell lung cancer (NSCLC) remains the most common cause of cancer-related death worldwide. Patients presenting with advanced-stage NSCLC have poor prognosis, while metastatic spread accounts for >70 % of patient's deaths. The major advances in the treatment of lung cancer have brought only minor improvements in survival; therefore, novel strategic treatment approaches are urgently needed. Accumulating data allocate a central role for the cancer microenvironment including mesenchymal stem cells (MSCs) in acquisition of drug resistance and disease relapse. Furthermore, studies indicate that translation initiation factors are over expressed in NSCLC and negatively impact its prognosis. Importantly, translation initiation is highly modulated by microenvironmental cues. Therefore, we decided to examine the effect of bone marrow MSCs (BM-MSCs) from normal donors on NSCLC cell lines with special emphasis on translation initiation mechanism in the crosstalk. We cultured NSCLC cell lines with BM-MSC conditioned media (i.e., secretome) and showed deleterious effects on the cells' proliferation, viability, death, and migration. We also demonstrated reduced levels of translation initiation factors implicated in cancer progression [eukaryotic translation initiation factor 4E (eIF4E) and eukaryotic translation initiation factor 4GI (eIF4GI)], their targets, and regulators. Finally, we outlined a mechanism by which BM-MSCs' secretome affected NSCLC's mitogen-activated protein kinase (MAPK) signaling pathway, downregulated the cell migration, and diminished translation initiation factors' levels. Taken together, our study demonstrates that there is direct dialogue between the BM-MSCs' secretome and NSCLC cells that manipulates translation initiation and critically affects cell fate. We suggest that therapeutic approach that will sabotage this dialogue, especially in the BM microenvironment, may diminish lung cancer metastatic spread and morbidity and improve the patient's life quality.

Human mesenchymal stem cells enhance cancer cell proliferation via IL-6 secretion and activation of ERK1/2

Human mesenchymal stem cells (hMSC) are frequently used in tissue engineering. Due to their strong tumor tropism, hMSC seem to be a promising vehicle for anticancer drugs. However, interactions between hMSC and cancer are ambiguous. Particularly the cytokines and growth factors seem to play an important role in cancer progression and metastasis. The present study evaluated the effects of hMSC on head and neck squamous cell carcinoma (HNSCC) cell lines (FaDu and HLaC78) in vitro. hMSC released several cytokines and growth factors. FaDu and HLaC78 showed a significant enhancement of cell proliferation after cultivation with hMSC-conditioned medium as compared to control. This proliferation improvement was inhibited by the addition of anti-IL-6. The western blot showed an activation of Erk1/2 in FaDu and HLaC78 by hMSC-conditioned medium. HNSCC cell lines expressed EGFR. The current study confirms the importance of cytokines secreted by hMSC in cancer biology. Especially IL-6 seems to play a key role in cancer progression. Thus, the use of hMSC as a carrier for cancer therapy must be discussed critically. Future studies should evaluate the possibility of generating genetically engineered hMSC with, for example, the absence of IL-6 secretion.

Roles of the Hippo pathway in lung development and tumorigenesis

Lung cancer is the most commonly diagnosed cancer and accounts for one fifth of all cancer deaths worldwide. Although significant progress has been made toward our understanding of the causes of lung cancer, the 5-year survival is still lower than 15%. Therefore, there is an urgent need for novel lung cancer biomarkers and drug targets. The Hippo signaling pathway is an emerging signaling pathway that regulates various biological processes. Recently, increasing evidence suggests that the Hippo pathway may play important roles in not only lung development but also lung tumorigenesis. In this review article, we will summarize the most recent advances and predict future directions on this new cancer research field.