IL‑17 induces NSCLC A549 cell proliferation via the upregulation of HMGA1, resulting in an increased cyclin D1 expression

circ-LIMK1 regulates cisplatin resistance in lung adenocarcinoma by targeting miR-512-5p/HMGA1 axis

This study aimed to unveil the detailed role and new mechanism of circ-LIMK1 in lung adenocarcinoma. Real-time quantitative polymerase chain reaction was performed to analyze the expression of circ-LIMK1, miR-512-5p, and HMGA1. 3-(4,5)-Dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide assay was employed to test the half maximal inhibitory concentration of cisplatin (DDP). Western blot was used to measure the expression of HMGA1, multidrug resistance protein 1, mitochondrial 37S ribosomal protein, and vascular endothelial growth factor A. Colony formation assay, flow cytometry, transwell assay, and tube formation assay were performed to analyze cell functions. Animal models were established to assay the role of circ-LIMK1 in vivo. The expression of circ-LIMK1 was up-regulated in DDP-resistant tumor tissues and cells. Knockdown of circ-LIMK1 reduced DDP resistance, impaired cancer cell growth, migration, invasion, and angiogenesis. circ-LIMK1 targeted miR-512-5p, and HMGA1 was targeted by miR-512-5p. MiR-512-5p absence could restore the repressive effects of circ-LIMK1 knockdown on lung adenocarcinoma cell phenotypes. Overexpression of HMGA1 could restore the inhibitory effects of miR-512-5p enrichment on lung adenocarcinoma cell malignant phenotypes. Knockdown of circ-LIMK1 could reduce growth of DDP-resistant tumors in vivo. Collectively, circ-LIMK1 regulated DDP resistance in lung adenocarcinoma by targeting miR-512-5p/HMGA1 axis.

Distribution and Clinical Significance of IL-17A in Tumor-Infiltrating Lymphocytes of Non-Small Cell Lung Cancer Patients

Objective: To investigate the distribution of IL-17A and its clinical significance in tumor infiltrating lymphocytes (TILs) of patients with non-small cell lung cancer (NSCLC).

Methods: Expression level of IL-17A in TILs of 3 paired NSCLC and paracancerous specimens was measured by qRT-PCR. The distribution of IL-17A in immune cell subsets of 15 paired NSCLC and paracancerous specimens was examined by flow cytometry. The correlation between IL-17A and clinical features of NSCLC was identified.

Results: IL-17A was significantly upregulated in TILs of NSCLC specimens than those of paracancerous ones (p < 0.0001). Meanwhile, T helper 17 cells (Th17 cells, p < 0.001), IL-17-secreting CD8⁺ T cells (Tc17 cells, p < 0.001) and IL-17-producing cells (γδT17 cells, p < 0.0001) were significantly abundant in TILs of NSCLC specimens than those of controls, and the higher abundance of the latter was much pronounced than that of the former two. Moreover, γδT17 cells in TILs were significantly correlated with lymphatic metastasis and CYFRA 21-1 level of NSCLC patients (p < 0.05).

Conclusion: Tumor infiltrated γδT cells are the main source of IL-17 in early-stage NSCLC, and IL-17 may be a vital regulator involved in the development of NSCLC.

HMGA1 stimulates MYH9-dependent ubiquitination of GSK-3β via PI3K/Akt/c-Jun signaling to promote malignant progression and chemoresistance in gliomas

Myosin heavy chain 9 (MYH9) plays an essential role in human diseases, including multiple cancers; however, little is known about its role in gliomas. In the present study, we revealed that HMGA1 and MYH9 were upregulated in gliomas and their expression correlated with WHO grade, and HMGA1 promoted the acquisition of malignant phenotypes and chemoresistance of glioma cells by regulating the expression of MYH9 through c-Jun-mediated transcription. Moreover, MYH9 interacted with GSK-3β to inhibit the expression of GSK-3β protein by promoting its ubiquitination; the downregulation of GSK-3β subsequently promoted the nuclear translocation of β-catenin, enhancing growth, invasion, migration, and temozolomide resistance in glioma cells. Expression levels of HMGA1 and MYH9 were significantly correlated with patient survival and should be considered as independent prognostic factors. Our findings provide new insights into the role of HMGA1 and MYH9 in gliomagenesis and suggest the potential application of HMGA1 and MYH9 in cancer therapy in the future.

Long-term PM2.5 exposure increases the risk of non-small cell lung cancer (NSCLC) progression by enhancing interleukin-17a (IL-17a)-regulated proliferation and metastasis

PM_2.5 is a class of airborne particles and droplets with sustained high levels in many developing countries. Epidemiological studies have indicated that PM_2.5 is closely associated with the increased morbidity and mortality of lung cancer in the world. Unfortunately, the effects of PM_2.5 on lung cancer are largely unknown. In the present study, we attempted to explore the role of PM_2.5 in the etiology of NSCLC. Here, we found that long-term PM_2.5 exposure led to significant pulmonary injury. Epithelial-mesenchymal transition (EMT) and cancer stem cells (CSC) properties were highly induced by PM_2.5 exposure. EMT was evidenced by the significant up-regulation of MMP2, MMP9, TGF-β1, α-SMA, Fibronectin and Vimentin. Lung cancer progression was associated with the increased expression of Kras, c-Myc, breast cancer resistance protein BCRP (ABCG2), OCT4, SOX2 and Aldh1a1, but the decreased expression of p53 and PTEN. Importantly, mice with IL-17a knockout (IL-17a^-/-) showed significantly alleviated lung injury and CSC properties following PM_2.5 exposure. Also, IL-17a^-/--attenuated tumor growth was recovered in PM_2.5-exposed mice injected with recombinant mouse IL-17a, accompanied with significantly restored lung metastasis. Taken together, these data revealed that PM_2.5 could promote the progression of lung cancer by enhancing the proliferation and metastasis through IL-17a signaling.

HMGA1 Modulates Gene Transcription Sustaining a Tumor Signalling Pathway Acting on the Epigenetic Status of Triple-Negative Breast Cancer Cells

Chromatin accessibility plays a critical factor in regulating gene expression in cancer cells. Several factors, including the High Mobility Group A (HMGA) family members, are known to participate directly in chromatin relaxation and transcriptional activation. The HMGA1 oncogene encodes an architectural chromatin transcription factor that alters DNA structure and interacts with transcription factors favouring their landing onto transcription regulatory sequences. Here, we provide evidence of an additional mechanism exploited by HMGA1 to modulate transcription. We demonstrate that, in a triple-negative breast cancer cellular model, HMGA1 sustains the action of epigenetic modifiers and in particular it positively influences both histone H3S10 phosphorylation by ribosomal protein S6 kinase alpha-3 (RSK2) and histone H2BK5 acetylation by CREB-binding protein (CBP). HMGA1, RSK2, and CBP control the expression of a set of genes involved in tumor progression and epithelial to mesenchymal transition. These results suggest that HMGA1 has an effect on the epigenetic status of cancer cells and that it could be exploited as a responsiveness predictor for epigenetic therapies in triple-negative breast cancers.

Comprehensive genomic and prognostic analysis of the IL‑17 family genes in lung cancer

The six members of the interleukin (IL)‑17 gene family (IL‑17A‑F) have been identified in various types of cancer. Although lung cancer is the leading cause of cancer‑related death worldwide and IL‑17A was found to play a critical role in lung cancer, there is little knowledge concerning the association between the other five members of the IL‑17 family and lung cancer. The genetic mutations and expression of IL‑17 family members were investigated using the Catalogue of Somatic Mutations in Cancer (COSMIC), Oncomine, and cBio Cancer Genomics Portal (cBioPortal) databases. Prognostic values and interaction networks of the members were assessed by the Kaplan‑Meier plotter, Search Tool for the Retrieval of Interacting Genes (STRING) database and FunRich software. The results found that, across 5,238 lung cancer patients in the cBioPortal, the results of IL‑17 family gene alteration frequencies and types showed that IL‑17A, IL‑25 and IL‑17F exhibited higher alteration frequencies (2, 2.1 and 1.9%, respectively), and gene amplification accounted for the majority of changes. IL‑17B, IL‑17C and IL‑17D exhibited lower alteration frequencies (0.8, 1.1 and 1.1%, respectively), and deep deletion accounted for the majority of changes. The rates of point mutations in IL‑17A through IL‑17F family genes in lung cancer were 0.66, 0.18, 0.13, 0.09, 0.27 and 0.44% in the COSMIC database. Within the Oncomine database, five datasets showed that IL‑17D was significantly decreased in lung cancer, while no dataset showed a significant difference in the expression of IL‑17A, IL‑17B, IL‑17C, IL‑25 or IL17‑F between lung cancer and normal controls. The frequencies of IL‑17A, IL‑17B and IL‑17C mRNA upregulation in lung squamous cell carcinoma were lower than those in lung adenocarcinoma (2.7, 1.9 and 2.1%, respectively), whereas the frequencies of IL‑17D, IL‑25 and IL‑17F mRNA upregulation were higher in lung squamous cell carcinoma than those in lung adenocarcinoma (3, 6 and 6%, respectively). IL‑17A and IL‑17B were unrelated to overall survival (p=0.11; P=0.17), whereas IL‑17C, IL‑17D, IL‑25 and IL‑17F influenced prognosis (P=0.0023, P=0.0059, P=0.039 and P=0.0017, respectively) according to the Kaplan‑Meier plotter. Moreover, the expression level of IL‑17C was the highest in lung tissues, and IL‑17 family genes mainly participate in the 'IFN‑γ pathway' according to the STRING database and Funrich software. In conclusion, we performed the first comprehensive investigation of the IL‑17 gene family in lung cancer, including gene mutation, mRNA expression levels, prognostic values and network pathways. Our results revealed that IL‑17 family gene mutation rates were in general low and that amplification and deep deletion were the main mutation type. The expression and function of IL‑17A and IL‑17B in lung cancer are still not fully elucidated and warrant research with larger sample sizes. IL‑17D was significantly decreased in lung cancer and was correlated with better OS. Studies of IL‑17C‑F in lung cancer are limited. Further experimental studies on the association between IL‑17D and lung cancer progression are needed to identify more effective therapeutic targets for lung cancer.

Targeting IL-17 attenuates hypoxia-induced pulmonary hypertension through downregulation of β-catenin

BACKGROUND

The role of interleukin 17 (IL-17) in hypoxic pulmonary hypertension (HPH) remains unclear. This study is designed to explore whether IL-17 is a potential target for HPH treatment.

METHODS

Clinic samples from the lung tissue and serum were obtained from qualified patients. Western blotting, immunohistochemistry and/or ELISA were used to measure the expression of relevant proteins. HPH models were established in C57BL/6 wild-type (WT) and IL-17 ^-/- mice and were treated with exogenous recombinant mouse IL-17 (rmIL-17) or an IL-17 neutralising antibody. Assays for cell proliferation, angiogenesis and adhesion were employed to analyse the behaviours of human pulmonary arterial endothelial cells (HPAECs). A non-contact Transwell coculture model was used to evaluate intercellular interactions.

RESULTS

Expression of IL-17 was increased in lung tissue of both patients with bronchiectasis/COPD-associated PH and HPH mouse model. Compared with WT mice, IL-17 ^-/- mice had attenuated HPH, whereas administration of rmIL-17 aggravated HPH. In vitro, recombinant human IL-17 (rhIL-17) promoted proliferation, angiogenesis and adhesion in HPAECs through upregulation of Wnt3a/β-catenin/CyclinD1 pathway, and siRNA-mediated knockdown of β-catenin almost completely reversed this IL-17-mediated phenomena. IL-17 promoted the proliferation but not the migration of human pulmonary arterial smooth muscle cells (HPASMCs) cocultured with HPAECs under both normoxia and hypoxia, but IL-17 had no direct effect on proliferation and migration of HPASMCs. Blockade of IL-17 with a neutralising antibody attenuated HPH in WT mice.

CONCLUSIONS

IL-17 contributes to the pathogenesis of HPH through upregulation of β-catenin expression. Targeting IL-17 might provide potential benefits for alternative therapeutic strategies for HPH.