The therapeutic potential of mesenchymal stem cells in lung cancer: benefits, risks and challenges

Imaging drug delivery to the lungs: Methods and applications in oncology

Direct delivery to the lung via inhalation is arguably one of the most logical approaches to treat lung cancer using drugs. However, despite significant efforts and investment in this area, this strategy has not progressed in clinical trials. Imaging drug delivery is a powerful tool to understand and develop novel drug delivery strategies. In this review we focus on imaging studies of drug delivery by the inhalation route, to provide a broad overview of the field to date and attempt to better understand the complexities of this route of administration and the significant barriers that it faces, as well as its advantages. We start with a discussion of the specific challenges for drug delivery to the lung via inhalation. We focus on the barriers that have prevented progress of this approach in oncology, as well as the most recent developments in this area. This is followed by a comprehensive overview of the different imaging modalities that are relevant to lung drug delivery, including nuclear imaging, X-ray imaging, magnetic resonance imaging, optical imaging and mass spectrometry imaging. For each of these modalities, examples from the literature where these techniques have been explored are provided. Finally the different applications of these technologies in oncology are discussed, focusing separately on small molecules and nanomedicines. We hope that this comprehensive review will be informative to the field and will guide the future preclinical and clinical development of this promising drug delivery strategy to maximise its therapeutic potential.

Therapeutic effects of mesenchymal stem cells loaded with oncolytic adenovirus carrying decorin on a breast cancer lung metastatic mouse model

Oncolytic adenoviruses (OAds) are alternative immune therapeutic strategies for tumors. However, liver uptake and antibody neutralization are two major barriers for systemic delivery during the treatment of tumor metastasis. Mesenchymal stem cells (MSCs) have emerged as potential vehicles to improve delivery. In this study, we loaded umbilical-cord-derived MSCs (UC-MSCs) with OAds expressing decorin (rAd.DCN) or without foreign genes (rAd.Null) to treat breast cancer lung metastasis. In vivo, rAd.Null, MSCs.Null, and rAd.DCN exhibited antitumor effects compared with other groups in a mouse model. Unexpectedly, MSCs.Null showed much greater antitumor responses than MSCs.DCN, including improved survival and reduced tumor burden. Compared with rAd.Null, both MSCs.Null and MSCs.DCN could improve the viral spread and distribution in metastatic tumor lesions in the lung. MSCs.DCN produced much more decorin in lungs than rAd.DCN; however, rAd.DCN reduced the downstream target genes of decorin much more strongly than MSCs.DCN, which was consistent with in vitro findings. In addition, rAd.DCN, MSCs.Null, and MSCs.DCN could reduce The cytokine levels in the lung. In conclusion, MSCs improved oncolytic adenoviral delivery and spread in tumor tissues and enhanced therapeutic effects. However, MSCs.DCN reduced OAd-evoked antitumor responses, possibly via a contact-dependent mechanism.

Mesenchymal stem cell-based treatments for COVID-19: status and future perspectives for clinical applications

As a result of cross-species transmission in December 2019, the coronavirus disease 2019 (COVID-19) became a serious endangerment to human health and the causal agent of a global pandemic. Although the number of infected people has decreased due to effective management, novel methods to treat critical COVID-19 patients are still urgently required. This review describes the origins, pathogenesis, and clinical features of COVID-19 and the potential uses of mesenchymal stem cells (MSCs) in therapeutic treatments for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected patients. MSCs have previously been shown to have positive effects in the treatment of lung diseases, such as acute lung injury, idiopathic pulmonary fibrosis, acute respiratory distress syndrome, lung cancer, asthma, and chronic obstructive pulmonary disease. MSC mechanisms of action involve differentiation potentials, immune regulation, secretion of anti-inflammatory factors, migration and homing, anti-apoptotic properties, antiviral effects, and extracellular vesicles. Currently, 74 clinical trials are investigating the use of MSCs (predominately from the umbilical cord, bone marrow, and adipose tissue) to treat COVID-19. Although most of these trials are still in their early stages, the preliminary data are promising. However, long-term safety evaluations are still lacking, and large-scale and controlled trials are required for more conclusive judgments regarding MSC-based therapies. The main challenges and prospective directions for the use of MSCs in clinical applications are discussed herein. In summary, while the clinical use of MSCs to treat COVID-19 is still in the preliminary stages of investigation, promising results indicate that they could potentially be utilized in future treatments.

Conditioned Media of Adipose-Derived Stem Cells Suppresses Sidestream Cigarette Smoke Extract Induced Cell Death and Epithelial-Mesenchymal Transition in Lung Epithelial Cells

The role of the epithelial-mesenchymal transition (EMT) in lung epithelial cells is increasingly being recognized as a key stage in the development of COPD, fibrosis, and lung cancers, which are all highly associated with cigarette smoking and with exposure to second-hand smoke. Using the exposure of human lung cancer epithelial A549 cells and non-cancerous Beas-2B cells to sidestream cigarette smoke extract (CSE) as a model, we studied the protective effects of adipose-derived stem cell-conditioned medium (ADSC-CM) against CSE-induced cell death and EMT. CSE dose-dependently induced cell death, decreased epithelial markers, and increased the expression of mesenchymal markers. Upstream regulator analysis of differentially expressed genes after CSE exposure revealed similar pathways as those observed in typical EMT induced by TGF-β1. CSE-induced cell death was clearly attenuated by ADSC-CM but not by other control media, such as a pass-through fraction of ADSC-CM or A549-CM. ADSC-CM effectively inhibited CSE-induced EMT and was able to reverse the gradual loss of epithelial marker expression associated with TGF-β1 treatment. CSE or TGF-β1 enhanced the speed of A549 migration by 2- to 3-fold, and ADSC-CM was effective in blocking the cell migration induced by either agent. Future work will build on the results of this in vitro study by defining the molecular mechanisms through which ADSC-CM protects lung epithelial cells from EMT induced by toxicants in second-hand smoke.

The Relationship Between Mesenchymal Stem Cells and Tumor Dormancy

Tumor dormancy, a state of tumor, is clinically undetectable and the outgrowth of dormant tumor cells into overt metastases is responsible for cancer-associated deaths. However, the dormancy-related molecular mechanism has not been clearly described. Some researchers have proposed that cancer stem cells (CSCs) and disseminated tumor cells (DTCs) can be seen as progenitor cells of tumor dormancy, both of which can remain dormant in a non-permissive soil/niche. Nowadays, research interest in the cancer biology field is skyrocketing as mesenchymal stem cells (MSCs) are capable of regulating tumor dormancy, which will provide a unique therapeutic window to cure cancer. Although the influence of MSCs on tumor dormancy has been investigated in previous studies, there is no thorough review on the relationship between MSCs and tumor dormancy. In this paper, the root of tumor dormancy is analyzed and dormancy-related molecular mechanisms are summarized. With an emphasis on the role of the MSCs during tumor dormancy, new therapeutic strategies to prevent metastatic disease are proposed, whose clinical application potentials are discussed, and some challenges and prospects of the studies of tumor dormancy are also described.

Lung-Resident Mesenchymal Stem Cell Fates within Lung Cancer

Simple Summary

Lung cancer remains the leading cause of cancer-related deaths worldwide. Herein, the heterogeneous tumor stroma decisively impacts on tumor progression, therapy resistance, and, thus, poor clinical outcome. Among the numerous non-epithelial cells constructing the complex environment of lung carcinomas, mesenchymal stem cells (MSC) gained attraction being stromal precursor cells that could be recruited and ‘educated’ by lung cancer cells to adopt a tumor-associated MSC phenotype, serve as source for activated fibroblasts and presumably for vascular mural cells finally reinforcing tumor progression. Lung-resident MSCs should be considered as ‘local MSCs in stand by’ ready to be arranged within the cancer stroma.

Abstract

Lung-resident mesenchymal stem cells (LR-MSCs) are non-hematopoietic multipotent stromal cells that predominately reside adventitial within lung blood vessels. Based on their self-renewal and differentiation properties, LR-MSCs turned out to be important regulators of normal lung homeostasis. LR-MSCs exert beneficial effects mainly by local secretion of various growth factors and cytokines that in turn foster pulmonary regeneration including suppression of inflammation. At the same time, MSCs derived from various tissues of origins represent the first choice of cells for cell-based therapeutic applications in clinical medicine. Particularly for various acute as well as chronic lung diseases, the therapeutic applications of exogenous MSCs were shown to mediate beneficial effects, hereby improving lung function and survival. In contrast, endogenous MSCs of normal lungs seem not to be sufficient for lung tissue protection or repair following a pathological trigger; LR-MSCs could even contribute to initiation and/or progression of lung diseases, particularly lung cancer because of their inherent tropism to migrate towards primary tumors and metastatic sites. However, the role of endogenous LR-MSCs to be multipotent tumor-associated (stromal) precursors remains to be unraveled. Here, we summarize the recent knowledge how ‘cancer-educated’ LR-MSCs impact on lung cancer with a focus on mesenchymal stem cell fates.

Flubendazole Elicits Antitumor Effects by Inhibiting STAT3 and Activating Autophagy in Non-small Cell Lung Cancer

Non-small cell lung carcinoma (NSCLC) is a major neoplastic disease with a high mortality worldwide; however, effective treatment of this disease remains a challenge. Flubendazole, a traditional anthelmintic drug, possesses potent antitumor properties; however, the detailed molecular mechanism of flubendazole activity in NSCLC needs to be further explored. In the present study, flubendazole was found to exhibit valid antitumor activity in vitro as well as in vivo. Flubendazole blocked phosphorylation of STAT3 in a dose- and time-dependent manner and regulated the transcription of STAT3 target genes encoding apoptotic proteins. Further, flubendazole inhibited STAT3 activation by inhibiting its phosphorylation and nuclear localization induced by interleukin-6 (IL-6). Notably, the autophagic flux of NSCLC cell lines was increased after flubendazole treatment. Furthermore, flubendazole downregulated the expression of BCL2, P62, and phosphorylated-mTOR, but it upregulated LC3-I/II and Beclin-1 expression, which are the main genes associated with autophagy. Collectively, these data contribute to elucidating the efficacy of flubendazole as an anticancer drug, demonstrating its potential as a therapeutic agent via its suppression of STAT3 activity and the activation of autophagy in NSCLC.

Lung Multipotent Stem Cells of Mesenchymal Nature: Cellular Basis, Clinical Relevance, and Implications for Stem Cell Therapy

Significance: Tissue-resident stem cells are essential for normal organ homeostasis as well as for functional tissue regeneration after severe injury. Herein, mesenchymal stem cells, also designated as mesenchymal stromal cells (MSCs), contribute to the maintenance of organ integrity by their ability to replace dysfunctional cells or secrete cytokines locally and thus support the repair and healing processes of affected tissues. Recent Advances: Besides epithelial stem and progenitor cells, substantial evidence exists that tissue-resident multipotent stem cells of mesenchymal nature also exist in adult human lungs. These lung MSCs may function to regulate pulmonary tissue repair and/or regeneration, inflammation, fibrosis, and tumor formation. Critical Issues: Although therapeutically applied MSCs turned out to be a valuable therapeutic option for the prevention of lung diseases and/or the regeneration of diseased lung tissue, the true function of tissue-resident MSCs within the lung, and identification of their niche, which presumably dictates function, remain elusive. Future Directions: A detailed understanding of lung MSC localization (in the potential vascular stem cell niche) as well as of the signaling pathways controlling stem cell fate is prerequisite to unravel how (i) endogenous MSCs contribute to lung diseases, (ii) exogenous MSCs affect the proliferation of endogenous stem cells to repair damaged tissue, and (iii) a potential on-site manipulation of these cells directly within their endogenous niche could be used for therapeutic benefits. This review focuses on the central role of lung-resident MSCs, which are closely associated with the pulmonary vasculature, in a variety of chronic and acute lung diseases. Antioxid. Redox Signal. 35, 204-216.

Silencing SIX1 by miR-7160 inhibits non-small cell lung cancer cell growth

The homeoprotein SIX1 is upregulated in non-small cell lung cancer (NSCLC) and associated with NSCLC tumorigenesis and progression. We identified microRNA-7160 (miR-7160) as a SIX1-targeting miRNA. RNA immunoprecipitation results confirmed a direct binding between miR-7160 and SIX1 mRNA in NSCLC cells. In the primary and established NSCLC cells, forced overexpression of miR-7160 downregulated SIX1 and inhibited cancer cell growth, proliferation, migration and invasion. Furthermore, miR-7160 overexpression induced apoptosis activation in NSCLC cells. Conversely, miR-7160 inhibition elevated SIX1 expression and enhanced NSCLC cell progression in vitro. Restoring SIX1 expression, by an untranslated region-depleted SIX1 expression construct, reversed miR-7160-induced anti-NSCLC cell activity. CRISPR/Cas9-inudced knockout of SIX1 mimicked miR-7160-induced actions and produced anti-NSCLC cell activity. In vivo, intratumoral injection of miR-7160-expressing lentivirus downregulated SIX1 mRNA and inhibited NSCLC xenograft growth in severe combined immunodeficient mice. Significantly, miR-7160 expression is downregulated in human NSCLC tissues and is correlated with SIX1 mRNA upregulation. Collectively, miR-7160 silenced SIX1 and inhibited NSCLC cell growth in vitro and in vivo.

Synergistic killing effect of paclitaxel and honokiol in non-small cell lung cancer cells through paraptosis induction

PURPOSE

Paclitaxel is an anticancer drug for the treatment of non-small cell lung cancer (NSCLC). However, drug-resistance remains a major problem. Honokiol is a natural component which has been found to exhibit anti-tumor activity. Paclitaxel and honokiol have been reported to be able to induce paraptosis. The aim of this study was to investigate whether honokiol can reverse paclitaxel resistance by inducing paraptosis in NSCLC cells.

METHODS

NSCLC cell lines H1650 (paclitaxel-sensitive), H1299 and H1650/PTX (intrinsic and acquired paclitaxel-resistant, respectively) were used to assess the cytotoxic effects of paclitaxel and honokiol. Light and transmission electron microscopy were performed to detect cytoplasmic vacuolation. In vitro cell viability and clonogenic survival assays, as well as in vivo xenograft assays were conducted to test synergistic killing effects of paclitaxel and honokiol on NSCLC cells. Western blotting, flow cytometry and immunofluorescence were performed to evaluate paraptosis-regulating mechanisms.

RESULTS

We found that combination treatment with paclitaxel and honokiol synergistically killed H1650, H1299 and H1650/PTX cells by inducing paraptosis, which is characterized by cytoplasmic vacuolation. Moreover, paclitaxel/honokiol treatment resulted in a significant growth delay in H1299 xenograft tumors that showed extensive cytoplasmic vacuolation. Mechanistically, proteasomal inhibition-mediated endoplasmic reticulum (ER) stress and unfolded protein responses leading to ER dilation, and the disruption of intracellular Ca2+ homeostasis and mitochondrial Ca2+ overload resulting in mitochondrial disfunction, were found to be involved in paclitaxel/honokiol-induced paraptosis. Cellular protein light chain 3 (LC3) may play an important role in paclitaxel/honokiol induced cytoplasmic vacuolation and NSCLC cell death.

CONCLUSIONS

Combination of honokiol and paclitaxel may represent a novel strategy for the treatment of paclitaxel-resistant NSCLC.

SLC6A8 is involved in the progression of non-small cell lung cancer through the Notch signaling pathway

Background

Solute carrier family 6 member 8 (SLC6A8) is known to be involved in the development of human tumors; however, the effect of SLC6A8 on the growth of non-small cell lung cancer (NSCLC) remains unclear. Here, we explored the role and potential action mechanism of SLC6A8 in NSCLC.

Methods

We used public databases [Oncomine, Gene Expression Omnibus (GEO), and The Cancer Genome Atlas (TCGA)] to explore the expression of SLC6A8 in NSCLC. Additionally, we used immunohistochemistry to detect the expression of SLC6A8 in NSCLC clinicopathological tissues (cancer and adjacent tissues) and Western blotting to detect the expression of SLC6A8 in NSCLC clinicopathological tissues, NSCLC cell lines (A549, H1299, H520, and H1975), and a normal epithelial cell line (BEAS-2B). Using overexpression and knockdown of the SLC6A8 gene, we analyzed the in vitro effects of SLC6A8 on the proliferation, invasion, and epithelial-mesenchymal transition (EMT) of NSCLC and also the possible molecular mechanism with Notch signaling pathway.

Results

Bioinformatic analysis demonstrated that SLC6A8 is highly expressed in NSCLC and is related to poor prognosis. We found that the expression of the SLC6A8 protein in human lung cancer tissues was significantly higher than that in adjacent tissues. In addition, it was also significantly higher in lung cancer cell lines (A549, H1299, H520, and H1975) than that in normal lung epithelium-BEAS-2B. Moreover, SLC6A8 overexpression promotes the proliferation, migration and invasion in vitro in NSCLC, accompanied by the activation of notch signaling pathway and the up-regulation of MMP9 and E-cadherin proteins. Knocking down SLC6A8 can inhibit the above effects on cells.

Conclusions

SLC6A8 promotes the malignant progression of NSCLC and activates the Notch signaling pathway. Therefore, SLC6A8 is expected to become a molecular target for NSCLC treatment.

TGF-β1-modified MSC-derived exosomal miR-135b attenuates cartilage injury via promoting M2 synovial macrophage polarization by targeting MAPK6

Osteoarthritis (OA) is the most common joint disease with an unsatisfactory therapy outcome and characterized by the degradation of articular cartilage and synovial inflammation. Here, we isolated bone marrow mesenchymal stem cells (BMSCs) from rat's bone marrow and BMSC-derived exosome (BMSCs-Exo) from BMSCs successfully. MiR-135b was proved to be highly expressed in TGF-β1-stimulated BMSC-derived exosomes (BMSCs-Exo^TGF-β1). Then, our results demonstrated that BMSCs-Exo^TGF-β1 reduced OA-induced upregulation of pro-inflammatory factors in rat's serum and damage in cartilage tissues, which was then reversed by miR-135b decreasing. Subsequently, we found that the OA-resulted M1 polarization of synovial macrophages (SMs) was repressed by BMSCs-Exo^TGF-β1, this effect of BMSCs-Exo^TGF-β1 was limited by miR-135b decreasing. We also proved that M2 polarization of SMs can be induced by miR-135b mimics. Furthermore, we found that the promotory effect of miR-135b and BMSCs-Exo^TGF-β1 on M2 SMs polarization was reversed by increasing of MAPK6. Overall, our data showed that BMSCs-Exo^TGF-β1 attenuated cartilage damage in OA rats through carrying highly expressed miR-135b. Mechanistically, miR-135b promoted M2 polarization of SMs through targeting MAPK6, thus improving cartilage damage. Our study provided a novel regulatory mechanism of BMSCs-Exo in OA development and revealed a new potential treatment target of OA.

Chronic Inflammation and Radiation-Induced Cystitis: Molecular Background and Therapeutic Perspectives

Radiation cystitis is a potential complication following the therapeutic irradiation of pelvic cancers. Its clinical management remains unclear, and few preclinical data are available on its underlying pathophysiology. The therapeutic strategy is difficult to establish because few prospective and randomized trials are available. In this review, we report on the clinical presentation and pathophysiology of radiation cystitis. Then we discuss potential therapeutic approaches, with a focus on the immunopathological processes underlying the onset of radiation cystitis, including the fibrotic process. Potential therapeutic avenues for therapeutic modulation will be highlighted, with a focus on the interaction between mesenchymal stromal cells and macrophages for the prevention and treatment of radiation cystitis.

Systematic profiling of immune signatures identifies prognostic predictors in lung adenocarcinoma

PURPOSE

Lung adenocarcinoma (LUAD) is the predominant subtype of lung cancer, with increasing evidence showing clinical benefits of immunotherapy. However, a lack of integrated profiles of complex LUAD immune microenvironments hampers the application of immunotherapy, resulting in limited eligible patient populations as well as drug resistance problems. Here, we aimed to systematically profile the immune signatures of LUADs and to assess the role of the immune microenvironment in patient outcome.

METHODS

We systematically profiled the immune signatures of LUADs deposited in the TCGA and GEO databases using a total of 730 immune-related genes. Differential expression analysis was used to identify dysregulated genes. Univariate Cox analysis followed by robust likelihood-based survival analysis and multivariate Cox analysis were applied to construct an immune-related prognostic model.

RESULTS

We found that differentially expressed immune genes were mainly enriched in immune cell proliferation, migration, activation and the NF-κB and TNF signaling pathways. The 10-immune gene predictive model that we constructed could differentiate LUAD patients with different overall survival times in several datasets, with areas under the curve (AUCs) of 0.67, 0.69, 0.72 and 0.74. LUAD patients with high- or low-risk scores exhibited distinct immune cell compositions, which may explain the prognostic significance of our model.

CONCLUSIONS

Our results add to the current knowledge of immune processes in LUADs and underscore the critical role of the immune microenvironment in LUAD patient outcome.

CircRNA BIRC6 promotes non-small cell lung cancer cell progression by sponging microRNA-145

PURPOSE

Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related mortality world-wide. Recently, a number of circular RNAs (circRNAs) has been found to be differentially expressed in human NSCLCs, correlating with clinico-pathological features. As yet, the expression and potential role of circRNA BIRC6 (circBIRC6) in NSCLC have not been studied.

METHODS

Expression of circBIRC6 and its target microRNA-145 (miR-145) in human NSCLC cells and tissues was assessed using qRT-PCR. In vitro genetic strategies were used to exogenously alter circBIRC6 and miR-145 expression. Their impact on in vitro and in vivo NSCLC cell behavior was studied.

RESULTS

We found that circBIRC6 was upregulated in primary human NSCLC tissues and NSCLC cells, whereas its potential target, miR-145, was downregulated. In A549 NSCLC cells and primary human NSCLC cells, shRNA-induced silencing of circBIRC6 potently inhibited their growth, proliferation, migration and invasion. Conversely, we found that exogenous overexpression of circBIRC6 promoted these characteristics. Using RNA immunoprecipitation (RIP) in A549 cells, we found that Argonaute 2 (Ago2) immunoprecipitated together with both circBIRC6 and miR-145. Additional studies revealed that the miR-145 level increased after circBIRC6 silencing in A549 cells, but decreased after circBIRC6 overexpression. Of note, we found that the circBIRC6 silencing-induced anti-A549 activity could be attenuated by a miR-145 inhibitor. Lastly, we found that circBIRC6 silencing inhibited the growth of NSCLC xenografts in severe combined immunodeficient mice.

CONCLUSIONS

From our data we conclude that circBIRC6 overexpression promotes NSCLC cell progression, possibly by sponging miR-145.

Overexpression of Progerin Results in Impaired Proliferation and Invasion of Non-Small Cell Lung Cancer Cells

Purpose

The accumulation of progerin (PG) in patients is responsible for the pathogenesis of Hutchinson-Gilford Progeria Syndrome (HGPS) because it triggers accelerated aging of cells. However, there are few studies on the effects of progerin on tumor cells. Lung cancer is one of the most common malignant cancers with high global morbidity and mortality rates; non-small cell lung cancer accounts for the majority of cases. The purpose of this study was to determine the effects of progerin on A549 cell proliferation, cell cycle, invasion, migration, sensitivity to DNA damaging agents, senescence and apoptosis with a goal of exploring new ideas for lung cancer treatment.

Methods

A549 cells overexpressing progerin (A549-PG) and a corresponding blank control (A549-GFP) were constructed by lentiviral infection. A nuclear staining assay was utilized to detect abnormal nuclear morphology. The proliferation, cell cycle, colony formation, invasion and migration abilities of A549-PG were compared with those of A549-GFP via EdU assays, flow cytometry, colony formation experiments, and Matrigel invasion and migration assays, respectively. SA‐β‐gal staining was used to measure senescence in cells.

Results

The expression of progerin was significantly higher in A549-PG than A549-GFP. About 20% of A549-PG possessed abnormal nuclei. Overexpression of progerin in A549 cells inhibited cell proliferation, migration and invasion, and associated proteins (CDK4, pRB, ANLN, MMP7 and MMP9) were downregulated. DNA damage repair was also impaired. Progerin did not cause cells to senesce, and there was no difference in apoptosis.

Conclusion

A549-PG generated some cellular changes, including the nuclear skeleton, the cell cycle, DNA damage repair, and migration and invasion abilities. Our data indicate that progerin could cause an imbalance in the steady state in A549 cells and increase their sensitivity to chemotherapeutic drugs.

IL-17A and IL-17F orchestrate macrophages to promote lung cancer

PURPOSE

Previously, inflammation has been found to be associated with the development of lung cancer. Despite their well-characterized pro-inflammatory functions, the putative roles of interleukin-17 (IL-17) cytokine family members in tumorigenesis have remained controversial. While IL-17A exhibits both pro- and anti-tumor effects, IL-17F has been suggested to serve as a candidate for cancer therapy. Thus, we aimed at clarifying the involvement of IL-17A/F in lung cancer.

METHODS

IL-17 receptor expression in human and murine lung cancer cells was assessed using immunofluorescence. The effect of IL-17A/F stimulation on lung cancer cell viability (SRB assay) and metabolism (glucose consumption and lactate production) was evaluated under normoxic and hypoxic conditions. Characterization of IL-17A/F-stimulated macrophages was performed by flow cytometry and ELISA. The effect of conditioned media (CM) from IL-17A/F-stimulated macrophages was evaluated on lung cancer cell migration. The effect of CM-stimulated macrophages on lung tumor growth, proliferation and angiogenesis was evaluated in vivo using a chicken chorioallantoic membrane (CAM) assay.

RESULTS

No alterations in lung cancer cell viability or metabolism were observed upon direct stimulation with IL-17A/F. We found, however, that CM from IL-17A/F-stimulated macrophages promoted both murine and human lung cancer cell progression through an increased migration capacity in vitro and enhanced in vivo tumor growth, proliferation and angiogenesis. These findings were supported by an increased polarization of human macrophages towards a M2-like phenotype.

CONCLUSIONS

Our data indicate that IL-17A/F act through immune cell orchestration, i.e., of macrophages, to promote lung cancer cell growth and progression. In addition, our data provide a link between IL-17A/F activity and lung cancer cell-macrophage crosstalk.

FAM83D promotes epithelial-mesenchymal transition, invasion and cisplatin resistance through regulating the AKT/mTOR pathway in non-small-cell lung cancer

PURPOSE

FAM83D has been proposed to act as an oncoprotein in several types of human cancer. Its role and mode of action in human non-small cell lung cancer (NSCLC) metastasis and its impact on chemotherapy are as yet, however, poorly understood.

METHODS

FAM83D expression was measured in NSCLC cells and normal lung epithelial cells, as well as in primary NSCLC tissues and corresponding adjacent non-cancerous tissues, using qRT-PCR, Western blotting and immunohistochemistry. FAM83D was stably overexpressed in BEAS2B cells or silenced in A549 and H1299 cells using retroviral or lentiviral vectors. The growth capacity of NSCLC cells was evaluated using MTT and colony formation assays. Epithelial-mesenchymal transition (EMT) was assessed using Western blotting and immunofluorescence. NSCLC cell invasive capacities were assessed using scratch wound healing and Boyden chamber assays. NSCLC cell viability in response to cisplatin treatment was assessed using MTT assays in vitro and a xenograft model in vivo.

RESULTS

We found that FAM83D expression levels were significantly elevated in NSCLC cells and tissues, and positively correlated with tumor progression and a poor prognosis. Exogenous FAM83D overexpression promoted, while FAM83D silencing inhibited NSCLC cell proliferation, EMT and invasion. FAM83D silencing also reduced cisplatin resistance. Concordantly, we found that NSCLC patients with a low FAM83D expression benefited most from chemotherapy. Mechanistically, we found that FAM83D activated the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway. Pharmacological treatment with either AKT or mTOR inhibitors reverted FAM83D-induced tumorigenic phenotypes.

CONCLUSIONS

Our results suggest a role of FAM83D in NSCLC development. In addition, our results indicate that NSCLC patients exhibiting FAM83D overexpression are likely to benefit from AKT and/or mTOR inhibitor treatment.

The Emerging Role of GC-MSCs in the Gastric Cancer Microenvironment: From Tumor to Tumor Immunity

Mesenchymal stem cells (MSCs) have been declared to not only participate in wound repair but also affect tumor progression. Tumor-associated MSCs, directly existing in the tumor microenvironment, play a critical role in tumor initiation, progression, and development. And different tumor-derived MSCs have their own unique characteristics. In this review, we mainly describe and discuss recent advances in our understanding of the emerging role of gastric cancer-derived MSC-like cells (GC-MSCs) in regulating gastric cancer progression and development, as well as the bidirectional influence between GC-MSCs and immune cells of the tumor microenvironment. Moreover, we also discuss the potential biomarker and therapeutic role of GC-MSCs. It is anticipated that new and deep insights into the functionality of GC-MSCs and the underlying mechanisms will promote the novel and promising therapeutic strategies against gastric cancer.