MicroRNAs - novel biomarkers for malignant pleural effusions

Pleural fluid microbiota as a biomarker for malignancy and prognosis

Malignant pleural effusions (MPE) complicate malignancies and portend worse outcomes. MPE is comprised of various components, including immune cells, cancer cells, and cell-free DNA/RNA. There have been investigations into using these components to diagnose and prognosticate MPE. We hypothesize that the microbiome of MPE is unique and may be associated with diagnosis and prognosis. We compared the microbiota of MPE against microbiota of pleural effusions from non-malignant and paramalignant states. We collected a total of 165 pleural fluid samples from 165 subjects; Benign (n = 16), Paramalignant (n = 21), MPE-Lung (n = 57), MPE-Other (n = 22), and Mesothelioma (n = 49). We performed high throughput 16S rRNA gene sequencing on pleural fluid samples and controls. We showed that there are compositional differences among pleural effusions related to non-malignant, paramalignant, and malignant disease. Furthermore, we showed differential enrichment of bacterial taxa within MPE depending on the site of primary malignancy. Pleural fluid of MPE-Lung and Mesothelioma were associated with enrichment with oral and gut bacteria that are commonly thought to be commensals, including Rickettsiella, Ruminococcus, Enterococcus, and Lactobacillales. Mortality in MPE-Lung is associated with enrichment in Methylobacterium, Blattabacterium, and Deinococcus. These observations lay the groundwork for future studies that explore host-microbiome interactions and their influence on carcinogenesis.

Regulatory Effect of let-7f Transfection in Non-Small Cell Lung Cancer on its Candidate Target Genes

BACKGROUND

Let-7f has essential impacts on biological processes; however, its biological and molecular functions in lung cancer pathogenesis have yet been remained unclear. We aimed to investigate the expression level of let-7f and its candidate target genes both in lung cancer tissues and A549 cell line.

METHODS

Bioinformatics databases were first used to select candidate target genes of let-7f. Then the relative gene and protein expressions of let-7f and its target genes, including HMGA2, ARID3B, SMARCAD1, and FZD3, were measured in lung tissues of NSCLC patients and A549 cell line using qRT-PCR and Western blotting. The electroporation method was used to transfect A549 cells with let-7f mimic and microRNA inhibitor. The impact of let-7f transfection on the viability of A549 cells was assessed using MTT assay. The expression data of studied genes were analyzed statistically.

RESULTS

Results indicated significant downregulated expression level of let-7f-5p (p = 0.0013) and upregulated level of the HMGA2 and FZD3 in NSCLC cases (p < 0.05). In A549 cells, after transfection with let-7f mimic, the expression of both mRNA and protein levels of HMGA2, ARID3B, SMARCAD1, and FZD3 decreased. Also, the overexpression of let-7f significantly inhibited the A549 cell proliferation and viability (p = 0.017).

CONCLUSION

Our findings exhibited the high value of let-7f and HMGA2 as biomarkers for NSCLC. The let-7f, as a major tumor suppressor regulatory factor via direct targeting genes (e.g. HMGA2), inhibits lung cancer cell viability and proliferation and could serve as a marker for the early diagnostic of NSCLC.

Regulatory Effect of let-7f Transfection in Non-Small Cell Lung Cancer on its Candidate Target Genes

BACKGROUND

Let-7f has essential impacts on biological processes; however, its biological and molecular functions in lung cancer pathogenesis have yet been remained unclear. We aimed to investigate the expression level of let-7f and its candidate target genes both in lung cancer tissues and A549 cell line.

METHODS

Bioinformatics databases were first used to select candidate target genes of let-7f. Then the relative gene and protein expressions of let-7f and its target genes, including HMGA2, ARID3B, SMARCAD1, and FZD3, were measured in lung tissues of NSCLC patients and A549 cell line using qRT-PCR and Western blotting. The electroporation method was used to transfect A549 cells with let-7f mimic and microRNA inhibitor. The impact of let-7f transfection on the viability of A549 cells was assessed using MTT assay. The expression data of studied genes were analyzed statistically.

RESULTS

Results indicated significant downregulated expression level of let-7f-5p (p = 0.0013) and upregulated level of the HMGA2 and FZD3 in NSCLC cases (p < 0.05). In A549 cells, after transfection with let-7f mimic, the expression of both mRNA and protein levels of HMGA2, ARID3B, SMARCAD1, and FZD3 decreased. Also, the overexpression of let-7f significantly inhibited the A549 cell proliferation and viability (p = 0.017).

CONCLUSION

Our findings exhibited the high value of let-7f and HMGA2 as biomarkers for NSCLC. The let-7f, as a major tumor suppressor regulatory factor via direct targeting genes (e.g. HMGA2), inhibits lung cancer cell viability and proliferation and could serve as a marker for the early diagnostic of NSCLC.

Troxerutin affects nephropathy signaling events in the kidney of type-1 diabetic male rats

Objective

Nephropathy is known to be the leading cause of kidney failure in diabetic patients. Troxerutin, as a flavonoid component, could provide a novel protective strategy in the prevention of diabetic nephropathy. A large number of reports on the salutary effects of troxerutin inspired us to investigate its effect on the nephropathy signaling events (i.e., expression of TGF-β, miRNA192, and SIP1) in type-1 induced diabetic rats.

Materials and Methods

50 male Wistar rats were divided into 5 groups including control group, sham group treated with troxerutin for 4 weeks, diabetic group induced by streptozotocin (STZ) injection, DI group including insulin-treated diabetic animals and DT group treated with troxerutin. Ultimately, rat kidneys were extracted, and the level of miR-192 (using qPCR), transforming growth factor-beta (TGF-β), and smad interacting protein 1 (SIP1) using an ELISA kit, was measured.

Results

The level of TGF-β and miRNA192 significantly increased in the diabetic group. However, their expression levels decreased following the administration of troxerutin and insulin (p<0.05) compared to control group. SIP1 was down-regulated in the diabetic group, whereas a spike in the expression levels was observed after troxerutin administration compared to control and troxerutin groups (p<0.05). However, no significant difference was found in the effects of insulin and troxerutin on the level of miR-192, SIP1, and TGF- β.

Conclusion

According to the previous literatures, during the progression of nephropathy, TGF-β represses SIP1 (the repression region in the collagen gene) by increasing the expression of miR-192. Ultimately, in this study, diabetes led to up-regulation of TGF-β while troxerutin proved to have a protective effect on the kidney by increasing SIP and lowering miR-192 levels.

Accelerated Wound Healing and Keratinocyte Proliferation through PI3K/Akt/pS6 and VEGFR2 Signaling by Topical Use of Pleural Fluid

Impaired wound healing is an ongoing issue that cancer patients undergoing chemotherapy or radiotherapy face. Our previous study regarding lung-cancer-associated pleural fluid (LCPF) demonstrated its propensity to promote endothelial proliferation, migration, and angiogenesis, which are crucial features during cutaneous wound healing. Therefore, the current study aimed to investigate the effect of pleural fluid on cutaneous wound closure in vitro and in vivo using HaCaT keratinocytes and a full-thickness skin wound model, respectively. Both heart-failure-associated pleural fluid (HFPF) and LCPF were sequentially centrifuged and filtered to obtain a cell-free status. Treatment with HFPF and LCPF homogeneously induced HaCaT proliferation with cell cycle progression, migration, and MMP2 upregulation. Western blotting revealed increased PI3K/Akt phosphorylation and VEGFR2/VEGFA expression in HaCaT cells. When treated with the PI3K inhibitor, LCPF-induced keratinocyte proliferation was attenuated with decreased pS6 levels. By applying the VEGFR2 inhibitor, LCPF-induced keratinocyte proliferation was ameliorated by pS6 and MMP2 downregulation. The effect of LCPF-induced cell junction rearrangement was disrupted by co-treatment with a VEGFR2 inhibitor. Compared with a 0.9% saline dressing, LCPF significantly accelerated wound closure and re-epithelization when used as a dressing material in a full-thickness wound model. Histological analysis revealed increased neo-epidermis thickness and dermis collagen synthesis in the LCPF-treated group. Furthermore, LCPF treatment activated basal keratinocytes at the wound edge with the upregulation of Ki-67, VEGFA, and MMP2. Our preliminaries provided the benefit of wet dressing with pleural fluid to improve cutaneous wound closure through enhanced re-epithelization and disclosed future autologous application in cancer wound treatment.

Molecular testing on serous effusion: An update

Cytological examination of the effusion fluid provides valuable information regarding the presence of malignancy. At times, it is challenging to diagnose malignant cells in serous effusion. The various ancillary techniques are available to solve the problem including immunocytochemistry, DNA ploidy, and multicolored flow cytometry. At present, the molecular tests on the effusion sample are of growing interest. The effusion sample is rich in cells and cell-free fluid that contains free DNA, cytokines, and extracellular vesicles. Molecular tests in effusion sample not only provide a diagnosis of malignancy but can also give valuable information that may be essential for the individualized therapy, management, and prognostic assessment. In this paper, we reviewed the application of the different molecular tests in the effusion sample.

Diving into the Pleural Fluid: Liquid Biopsy for Metastatic Malignant Pleural Effusions

Simple Summary

Malignant pleural effusion is a common complication arising as the natural progression of many tumors, such as lung cancer. When this occurs, the common protocol consists of analyzing the pleural fluid for the presence of malignant cells. However, on many occasions no malignant cells are found despite a clear suspicion of cancer. Thus, the current diagnostic methodology is imperfect and more precise methods for the identification of malignancy are needed. Nonetheless, these methods are often invasive, which may be counterproductive, especially for patients with poor health condition. These concerns have made clinicians consider alternative non-invasive strategies to diagnose cancer using the generally abundant pleural fluid (e.g., liquid biopsy). Thus, a liquid sample can be analyzed for the presence of cancer footprints, such as circulating malignant cells and tumor nucleic acids. Herein, we review the literature for studies considering pleural fluid as a successful source of liquid biopsy.

Abstract

Liquid biopsy is emerging as a promising non-invasive diagnostic tool for malignant pleural effusions (MPE) due to the low sensitivity of conventional pleural fluid (PF) cytological examination and the difficulty to obtain tissue biopsies, which are invasive and require procedural skills. Currently, liquid biopsy is increasingly being used for the detection of driver mutations in circulating tumor DNA (ctDNA) from plasma specimens to guide therapeutic interventions. Notably, malignant PF are richer than plasma in tumor-derived products with potential clinical usefulness, such as ctDNA, micro RNAs (miRNAs) and long non-coding RNAs (lncRNAs), and circulating tumor cells (CTC). Tumor-educated cell types, such as platelets and macrophages, have also been added to this diagnostic armamentarium. Herein, we will present an overview of the role of the preceding biomarkers, collectively known as liquid biopsy, in PF samples, as well as the main technical approaches used for their detection and quantitation, including a proper sample processing. Technical limitations of current platforms and future perspectives in the field will also be addressed. Using PF as liquid biopsy shows promise for use in current practice to facilitate the diagnosis and management of metastatic MPE.

Pleural biomarkers in diagnostics of malignant pleural effusion: a narrative review

Although cytology and pleural biopsy of pleural effusion (PE) are the gold standards for diagnosing malignant pleural effusion (MPE), these tools’ diagnostic accuracy is plagued by some limitations such as low sensitivity, considerable inter-observer variation and invasiveness. The assessment of PE biomarkers may hence be seen as an objective and non-invasive diagnostic alternative in MPE diagnostics. In this review, we summarize the characteristics and diagnostic accuracy of available PE biomarkers, including carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), carbohydrate antigens 125 (CA125), carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 15-3 (CA15-3), a fragment of cytokeratin 19 (CYFRA 21-1), chitinase-like proteins (CLPs), vascular endothelial growth factor (VEGF) and its soluble receptor, endostatin, calprotectin, cancer ratio, homocysteine, apolipoprotein E (Apo-E), B7 family members, matrix metalloproteinase (MMPs) and tissue-specific inhibitors of metalloproteinases (TIMPs), reactive oxygen species modulator 1 (Romo1), tumor-associated macrophages (TAMs) and monocytes, epigenetic markers (e.g., cell-free microRNA and mRNA). We summarized the evidence from systematic review and meta-analysis for traditional tumor markers’ diagnostic accuracy. According to the currently available evidence, we conclude that the traditional tumor markers have high specificity (around 0.90) but low sensitivity (around 0.50). The diagnostic accuracy of novel tumor markers needs to be validated by further studies. None of these tumor biomarkers would have sufficient diagnostic accuracy to confirm or exclude MPE when used alone. A multi-biomarker strategy, also encompassing the use of artificial intelligence algorithms, may be a valuable perspective for improving the diagnostic accuracy of MPE.

Liquid biopsy approaches for pleural effusion in lung cancer patients

Genomic profiling of tumors has become the mainstay for diagnosis, treatment monitoring and a guide to precision medicine. However, in clinical practice, the detection of driver mutations in tumors has several procedural limitations owing to progressive disease and tumor heterogeneity. The current era of liquid biopsy promises a better solution. This diagnostic utility of liquid biopsy has been demonstrated by numerous studies for the detection of cell-free DNA (cfDNA) in plasma for disease diagnosis, prognosis, and prediction. However, cfDNAs are limited in blood circulation and still hurdles to achieve promising precision medicine. Malignant pleural effusion (MPE) is usually detected in advanced lung malignancy, which is rich in tumor cells. Extracellular vesicles and cfDNAs are the two major targets currently explored using MPE. Therefore, MPE can be used as a source of biomarkers in liquid biopsy for investigating tumor mutations. This review focuses on the liquid biopsy approaches for pleural effusion which may be explored as an alternative source for liquid biopsy in lung cancer patients to diagnose early disease progression.

Propofol suppresses the progression of non‑small cell lung cancer via downregulation of the miR‑21‑5p/MAPK10 axis

Non‑small cell lung cancer (NSCLC) accounts for >80% of lung cancer cases and is the leading cause of cancer‑associated mortality worldwide. Propofol is an anesthetic drug frequently used during tumor resection. It is also known to exert inhibitory effects on cancer. Although the role of propofol in NSCLC has been reported, its underlying mechanisms remain unknown. The present study aimed therefore to investigate the mechanisms of propofol action on NSCLC. Starbase V3.0 project was used to analyze the expression levels of microRNA‑21‑5p (miR‑21‑5p) and mitogen‑activated protein kinase 10 (MAPK10) in NSCLC and adjacent normal tissues from patients with NSCLC and the association between miR‑21‑5p and MAPK10 expression level in NSCLC tissues. The correlation between MAPK10 expression and disease‑free survival (DFS) in patients with NSCLC was analyzed using GEPIA software version 1.0. miR‑21‑5p and MAPK10 expression in tumor and adjacent normal tissues from patients with NSCLC was evaluated by reverse transcription‑quantitative (RT‑q) PCR and western blotting. Cell viability and apoptosis were assessed by using Cell Counting Kit‑8 assay and flow cytometry, respectively. The interaction between miR‑21‑5p and MAPK10 was predicted by TargetScan/miRanda and verified by dual luciferase assay. The regulatory effect of propofol on miR‑21‑5p and MAPK10 expression in NSCLC cell lines was examined by RT‑qPCR and western blotting. Starbase V3.0 project and the results of the present study indicated that tumor tissues presented a significantly lower MAPK10 level and a higher miR‑21‑5p level compared with the normal samples, and that miR‑21‑5p expression was negatively correlated with MAPK10 expression in the tumor tissues of patients with NSCLC. Furthermore, miR‑21‑5p targeted the 3'‑untranslated region of MAPK10. In addition, compared with BEAS‑2B cells, a higher miR‑21‑5p and a lower MAPK10 expression was observed in the NSCLC cell lines A549 and H1299, which was reversed by propofol. The overexpression of miR‑21‑5p abrogated the effects of propofol on A549 and H1299 cell viability and apoptosis by targeting MAPK10. Taken together, these findings demonstrated that propofol inhibited the viability and promoted the apoptosis of NSCLC cells by downregulating the miR‑21‑5p/MAPK10 axis.