miR-26a desensitizes non-small cell lung cancer cells to tyrosine kinase inhibitors by targeting PTPN13

The emerging role of noncoding RNAs in the EGFR signaling pathway in lung cancer

Noncoding ribonucleic acids (ncRNAs) have surfaced as essential orchestrators within the intricate system of neoplastic biology. Specifically, the epidermal growth factor receptor (EGFR) signalling cascade shows a central role in the etiological underpinnings of pulmonary carcinoma. Pulmonary malignancy persists as a preeminent contributor to worldwide mortality attributable to malignant neoplasms, with non-small cell lung carcinoma (NSCLC) emerging as the most predominant histopathological subcategory. EGFR is a key driver of NSCLC, and its dysregulation is frequently associated with tumorigenesis, metastasis, and resistance to therapy. Over the past decade, researchers have unveiled a complex network of ncRNAs, encompassing microRNAs, long noncoding RNAs, and circular RNAs, which intricately regulate EGFR signalling. MicroRNAs, as versatile post-transcriptional regulators, have been shown to target various components of the EGFR pathway, influencing cancer cell proliferation, migration, and apoptosis. Additionally, ncRNAs have emerged as critical modulators of EGFR signalling, with their potential to act as scaffolds, decoys, or guides for EGFR-related proteins. Circular RNAs, a relatively recent addition to the ncRNA family, have also been implicated in EGFR signalling regulation. The clinical implications of ncRNAs in EGFR-driven lung cancer are substantial. These molecules exhibit diagnostic potential as robust biomarkers for early cancer detection and personalized treatment. Furthermore, their predictive value extends to predicting disease progression and therapeutic outcomes. Targeting ncRNAs in the EGFR pathway represents a novel therapeutic approach with promising results in preclinical and early clinical studies. This review explores the increasing evidence supporting the significant role of ncRNAs in modulating EGFR signalling in lung cancer, shedding light on their potential diagnostic, prognostic, and therapeutic implications.

miR-200b, ZEB2 and PTPN13 Are Downregulated in Colorectal Carcinoma with Serosal Invasion

Serosal invasion is an independent negative prognostic factor in certain cancers, including CRC. However, the mechanisms behind serosal invasion are poorly understood. We therefore assumed that epithelial-mesenchymal transition (EMT) might be involved. Our study included 34 patients with CRC, 3 stage pT2, 14 stage pT3 and 17 showing serosal invasion (stage pT4a according to TNM staging system). RNA isolated from formalin-fixed paraffin-embedded tissue samples was analysed for expression of the miR-200 family and their target genes CDKN1B, ONECUT2, PTPN13, RND3, SOX2, TGFB2 and ZEB2 using real-time PCR. We found upregulation of miR-200b and ONECUT2 in CRC pT3 and pT4a compared to normal mucosa, and downregulation of CDKN1B in CRC pT3. Moreover, we observed, downregulation of miR-200b, PTPN13 and ZEB2 in CRC with serosal invasion (pT4a) compared to pT3. Our results suggest the involvement of partial EMT in serosal invasion of CRC. In addition, PTPN13 seems to be one of the important regulators involved in serosal invasion, and ONECUT2 in tumour growth.

Critical roles of PTPN family members regulated by non-coding RNAs in tumorigenesis and immunotherapy

Since tyrosine phosphorylation is reversible and dynamic in vivo, the phosphorylation state of proteins is controlled by the opposing roles of protein tyrosine kinases (PTKs) and protein tyrosine phosphatase (PTPs), both of which perform critical roles in signal transduction. Of these, intracellular non-receptor PTPs (PTPNs), which belong to the largest class I cysteine PTP family, are essential for the regulation of a variety of biological processes, including but not limited to hematopoiesis, inflammatory response, immune system, and glucose homeostasis. Additionally, a substantial amount of PTPNs have been identified to hold crucial roles in tumorigenesis, progression, metastasis, and drug resistance, and inhibitors of PTPNs have promising applications due to striking efficacy in antitumor therapy. Hence, the aim of this review is to summarize the role played by PTPNs, including PTPN1/PTP1B, PTPN2/TC-PTP, PTPN3/PTP-H1, PTPN4/PTPMEG, PTPN6/SHP-1, PTPN9/PTPMEG2, PTPN11/SHP-2, PTPN12/PTP-PEST, PTPN13/PTPL1, PTPN14/PEZ, PTPN18/PTP-HSCF, PTPN22/LYP, and PTPN23/HD-PTP, in human cancer and immunotherapy and to comprehensively describe the molecular pathways in which they are implicated. Given the specific roles of PTPNs, identifying potential regulators of PTPNs is significant for understanding the mechanisms of antitumor therapy. Consequently, this work also provides a review on the role of non-coding RNAs (ncRNAs) in regulating PTPNs in tumorigenesis and progression, which may help us to find effective therapeutic agents for tumor therapy.

MicroRNAs as the critical regulators of tyrosine kinase inhibitors resistance in lung tumor cells

Lung cancer is the second most common and the leading cause of cancer related deaths globally. Tyrosine Kinase Inhibitors (TKIs) are among the common therapeutic strategies in lung cancer patients, however the treatment process fails in a wide range of patients due to TKIs resistance. Given that the use of anti-cancer drugs can always have side effects on normal tissues, predicting the TKI responses can provide an efficient therapeutic strategy. Therefore, it is required to clarify the molecular mechanisms of TKIs resistance in lung cancer patients. MicroRNAs (miRNAs) are involved in regulation of various pathophysiological cellular processes. In the present review, we discussed the miRNAs that have been associated with TKIs responses in lung cancer. MiRNAs mainly exert their role on TKIs response through regulation of Tyrosine Kinase Receptors (TKRs) and down-stream signaling pathways. This review paves the way for introducing a panel of miRNAs for the prediction of TKIs responses in lung cancer patients.

PTPL1 suppresses lung cancer cell migration via inhibiting TGF-β1-induced activation of p38 MAPK and Smad 2/3 pathways and EMT

Epithelial-mesenchymal transition (EMT) enables dissemination of neoplastic cells and onset of distal metastasis of primary tumors. However, the regulatory mechanisms of EMT by microenvironmental factors such as transforming growth factor-β (TGF-β) remain largely unresolved. Protein tyrosine phosphatase L1 (PTPL1) is a non-receptor protein tyrosine phosphatase that plays a suppressive role in tumorigenesis of diverse tissues. In this study we investigated the role of PTPL1/PTPN13 in metastasis of lung cancer and the signaling pathways regulated by PTPL1 in terms of EMT of non-small cell lung cancer (NSCLC) cells. We showed that the expression of PTPL1 was significantly downregulated in cancerous tissues of 23 patients with NSCLC compared with adjacent normal tissues. PTPL1 expression was positively correlated with overall survival of NSCLC patients. Then we treated A549 cells in vitro with TGF-β1 (10 ng/mL) and assessed EMT. We found that knockdown of PTPL1 enhanced the migration and invasion capabilities of A549 cells, through enhancing TGF-β1-induced EMT. In nude mice bearing A549 cell xenografts, knockdown of PTPL1 significantly promoted homing of cells and formation of tumor loci in the lungs. We further revealed that PTPL1 suppressed TGF-β-induced EMT by counteracting the activation of canonical Smad2/3 and non-canonical p38 MAPK signaling pathways. Using immunoprecipitation assay we demonstrated that PTPL1 could bind to p38 MAPK, suggesting that p38 MAPK might be a direct substrate of PTPL1. In conclusion, these results unravel novel mechanisms underlying the regulation of TGF-β signaling pathway, and have implications for prognostic assessment and targeted therapy of metastatic lung cancer.

Molecular Insights into the Recruiting Between UCP2 and DDX5/UBAP2L in the Metabolic Plasticity of Non-Small-Cell Lung Cancer

Mitochondrial uncoupling protein 2 (UCP2) is distributed in tumor cells with a link to the support of systemic metabolic deregulation, and the downregulation of UCP2 has been unveiled as a biomarker of oncogenesis and chemoresistance in non-small-cell lung cancer (NSCLC) cells. However, the underlying mechanism of how UCP2 cooperates with other proteins in this metabolic reprogramming remains largely unsolved. We employed a combined computational and experimental strategy to explore into the recruiting of DDX5 with other proteins, and we unraveled the underlying structural mechanisms. We found that recruiting by ATP-dependent RNA helicase DDX5 (DDX5)/ubiquitin-associated protein 2-like (UBAP2L) might help UCP2 to play the pathological roles in NSCLC cells. According to the view of thermodynamics in physics, UCP2 tends to recruit DDX5 rather than UBAP2L, as shown by the ensemble-based docking, molecular dynamics simulations and molecular mechanics generalized Born surface area (MM/GBSA) approach. Cellular immunofluorescence assays further demonstrated that UCP2 associate with DDX5, and the recruiting of DDX5 with UCP2 at least partially contribute to the metabolic plasticity of NSCLCs via the AKT/mTOR pathway. Our study proposed an efficient way for detecting the protein-protein association via the experimentally validated molecular simulation. Our results shed light on the functional annotation of UCP and DDX family proteins in dysregulated metabolism, and the identification of candidate therapeutic targets for NSCLC.

Dual Role of the PTPN13 Tyrosine Phosphatase in Cancer

In this review article, we present the current knowledge on PTPN13, a class I non-receptor protein tyrosine phosphatase identified in 1994. We focus particularly on its role in cancer, where PTPN13 acts as an oncogenic protein and also a tumor suppressor. To try to understand these apparent contradictory functions, we discuss PTPN13 implication in the FAS and oncogenic tyrosine kinase signaling pathways and in the associated biological activities, as well as its post-transcriptional and epigenetic regulation. Then, we describe PTPN13 clinical significance as a prognostic marker in different cancer types and its impact on anti-cancer treatment sensitivity. Finally, we present future research axes following recent findings on its role in cell junction regulation that implicate PTPN13 in cell death and cell migration, two major hallmarks of tumor formation and progression.

PTPN13 acts as a tumor suppressor in clear cell renal cell carcinoma by inactivating Akt signaling

Protein tyrosine phosphatase, nonreceptor type 13 (PTPN13), has emerged as a critical cancer-related gene that is implicated in a wide range of cancer types. However, the role of PTPN13 in clear cell renal cell carcinoma (ccRCC) is poorly understood. In the present study, we aimed to evaluate whether PTPN13 participates in the progression of ccRCC. Decreased expression of PTPN13 was found in ccRCC tissues, which predicted a shorter survival rate in ccRCC patients. PTPN13 expression was also lower in ccRCC cell lines, and the upregulation of PTPN13 repressed the proliferation, colony formation and invasion, but enhanced the apoptosis of ccRCC cells. In contrast, the silencing of PTPN13 produced the opposite effects. Further data showed that PTPN13 overexpression decreased the phosphorylation of Akt, while PTPN13 silencing increased the phosphorylation of Akt. Treatment with Akt inhibitor markedly abrogated the PTPN13 silencing-evoked oncogenic effect in ccRCC cells. Xenograft tumor experiments revealed that overexpression of PTPN13 remarkably restricted the tumor formation and growth of ccRCC cells in vivo associated with inactivation of Akt. In conclusion, our data demonstrated that overexpression of PTPN13 restricts the proliferation and invasion of ccRCC cells through inactivation of Akt. Our study suggests a tumor suppressive function of PTPN13 in ccRCC and highlights the potential role of PTPN13 in the progression of ccRCC.

PTPN13 induces cell junction stabilization and inhibits mammary tumor invasiveness

Clinical data suggest that the protein tyrosine phosphatase PTPN13 exerts an anti-oncogenic effect. Its exact role in tumorigenesis remains, however, unclear due to its negative impact on FAS receptor-induced apoptosis.

Methods: We crossed transgenic mice deleted for PTPN13 phosphatase activity with mice that overexpress human HER2 to assess the exact role of PTPN13 in tumor development and aggressiveness. To determine the molecular mechanism underlying the PTPN13 tumor suppressor activity we developed isogenic clones of the aggressive human breast cancer cell line MDA-MB-231 overexpressing either wild type or a catalytically-inactive mutant PTPN13 and subjected these to phosphoproteomic and gene ontology analyses.

We investigated the PTPN13 consequences on cell aggressiveness using wound healing and Boyden chamber assays, on intercellular adhesion using videomicroscopy, cell aggregation assay and immunofluorescence.

Results: The development, growth and invasiveness of breast tumors were strongly increased by deletion of the PTPN13 phosphatase activity in transgenic mice. We observed that PTPN13 phosphatase activity is required to inhibit cell motility and invasion in the MDA-MB-231 cell line overexpressing PTPN13. In vivo, the negative PTPN13 effect on tumor invasiveness was associated with a mesenchymal-to-epithelial transition phenotype in athymic mice xenografted with PTPN13-overexpressing MDA-MB-231 cells, as well as in HER2-overexpressing mice with wild type PTPN13, compared to HER2-overexpressing mice that lack PTPN13 phosphatase activity. Phosphoproteomic and gene ontology analyses indicated a role of PTPN13 in the regulation of intercellular junction-related proteins. Finally, protein localization studies in MDA-MB-231 cells and HER2-overexpressing mice tumors confirmed that PTPN13 stabilizes intercellular adhesion and promotes desmosome formation.

Conclusions: These data provide the first evidence for the negative role of PTPN13 in breast tumor invasiveness and highlight its involvement in cell junction stabilization.

miR- 26a Sensitizes Melanoma Cells To Dabrafenib Via Targeting HMGB1-Dependent Autophagy Pathways

Background

Melanoma is known as the most aggressive and lethal type of cutaneous cancer due to its rapid development of drug resistance to chemotherapy drugs.

Methods

In our study, we conducted a variety of studies, including quantitative PCR, Western blot, and autophagy and apoptosis assays to investigate the involvement of miR-26a and HMGB1 in modulation of dabrafenib sensitivity in human melanoma cell lines.

Results

Our studies revealed that the expressions of miR-26a and HMGB1 were altered in two melanoma cell lines after dabrafenib treatment. Additionally, dabrafenib caused autophagy in melanoma and this autophagic process was regulated by miR-26a via modifying HMGB1 expression. Furthermore, silencing HMGB1-inhibited autophagy induced by dabrafenib in melanoma cells. Last, we verified that treatment with a miR-26a mimic and HMGB1 shRNA could increase the efficacy of dabrafenib in melanoma cells.

Conclusion

Taken together, we showed that miR-26a is involved in the regulation of dabrafenib efficacy via a HMGB1-dependent autophagy pathway in melanoma cells. These results shed light on a novel treatment for conventional dabrafenib-based chemotherapy for melanoma.

Crosstalk between the Akt/mTORC1 and NF-κB signaling pathways promotes hypoxia-induced pulmonary hypertension by increasing DPP4 expression in PASMCs

Abnormal wound healing by pulmonary artery smooth muscle cells (PASMCs) promotes vascular remodeling in hypoxia-induced pulmonary hypertension (HPH). Increasing evidence shows that both the mammalian target of rapamycin complex 1 (mTORC1) and nuclear factor-kappa B (NF-κB) are involved in the development of HPH. In this study, we explored the crosstalk between mTORC1 and NF-κB in PASMCs cultured under hypoxic condition and in a rat model of hypoxia-induced pulmonary hypertension (HPH). We showed that hypoxia promoted wound healing of PASMCs, which was dose-dependently blocked by the mTORC1 inhibitor rapamycin (5-20 nM). In PASMCs, hypoxia activated mTORC1, which in turn promoted the phosphorylation of NF-κB. Molecular docking revealed that mTOR interacted with IκB kinases (IKKs) and that was validated by immunoprecipitation. In vitro kinase assays and mass spectrometry demonstrated that mTOR phosphorylated IKKα and IKKβ separately. Inhibition of mTORC1 decreased the level of phosphorylated IKKα/β, thus reducing the phosphorylation and transcriptional activity of NF-κB. Bioinformatics study revealed that dipeptidyl peptidase-4 (DPP4) was a target gene of NF-κB; DPP4 inhibitor, sitagliptin (10-500 μM) effectively inhibited the abnormal wound healing of PASMCs under hypoxic condition. In the rat model of HPH, we showed that NF-κB activation (at 3 weeks) was preceded by mTOR signaling activation (after 1 or 2 weeks) in lungs, and administration of sitagliptin (1-5 mg/kg every day, ig) produced preventive effects against the development of HPH. In conclusion, hypoxia activates the crosstalk between mTORC1 and NF-κB, and increased DPP4 expression in PASMCs that leads to vascular remodeling. Sitagliptin, a DPP4 inhibitor, exerts preventive effect against HPH.

The Importance of microRNAs in RAS Oncogenic Activation in Human Cancer

microRNAs (miRNAs) regulate gene expression by modulating the translation of protein-coding RNAs. Their aberrant expression is involved in various human diseases, including cancer. Here, we summarize the experimental pieces of evidence that proved how dysregulated miRNA expression can lead to RAS (HRAS, KRAS, or NRAS) activation irrespective of their oncogenic mutations. These findings revealed relevant pathogenic mechanisms as well as mechanisms of resistance to target therapies. Based on this knowledge, potential approaches for the control of RAS oncogenic activation can be envisioned.

miR-26a suppresses osteosarcoma migration and invasion by directly targeting HMGA1

Osteosarcoma (OS) is identified as the most commonly diagnosed malignant cancer of bone, and has approximately three million new cases annually. miR-26a plays an important role in the development of various types of cancer. We investigated whether miR-26a can regulate the migration and invasion of OS by targeting high-mobility group A1 HMGA1. Western blot analysis was used to identify the changes of protein levels. Reverse transcription-quantitative PCR was used to test expression levels of genes and miR-26a. Luciferase reporter assay was used to test the specific target gene of miR-26a. Transwell assay was employed to determine the migration and invasion of OS cell lines. In the present study, miRNA-26a was frequently downregulated in OS tissues and cells. Overexpression of miR-26a inhibited cell migration and invasion in vitro. In addition, miR-26a downregulated HMGA1 by targeting its 3′-UTR and knockdown of HMGA1 significantly suppressed the migration and invasion of two osteosarcoma cell lines in vitro. miR-26a suppressed the migration and invasion of OS cells by targeting HMGA1, suggesting that miR-26a/HMGA1 axis provides a new prospective therapeutic strategy for OS.

[MicroRNA-26a and Tumor]

微小RNA（microRNAs, miRNAs）是一类由20个-22个核苷酸组成的小片段非编码RNA，通过靶向结合基因mRNA的3’非翻译区（3’-UTR）调控其表达。许多研究报道miRNAs参与肿瘤的发生发展。MiR-26a在不同的肿瘤中发挥不同的作用，在肿瘤增殖、转移侵袭、血管形成、生物代谢及诊断预后中都有作用。本文就miR-26a与肿瘤关系的研究进展进行综述。

Cefminox, a Dual Agonist of Prostacyclin Receptor and Peroxisome Proliferator-Activated Receptor-Gamma Identified by Virtual Screening, Has Therapeutic Efficacy against Hypoxia-Induced Pulmonary Hypertension in Rats

Prostacyclin receptor (IP) and peroxisome proliferator-activated receptor-gamma (PPARγ) are both potential targets for treatment of pulmonary arterial hypertension (PAH). Expression of IP and PPARγ decreases in PAH, suggesting that screening of dual agonists of IP and PPARγ might be an efficient method for drug discovery. Virtual screening (VS) of potential IP-PPARγ dual-targeting agonists was performed in the ZINC database. Ten of the identified compounds were further screened, and cefminox was found to dramatically inhibit growth of PASMCs with no obvious cytotoxicity. Growth inhibition by cefminox was partially reversed by both the IP antagonist RO113842 and the PPARγ antagonist GW9662. Investigation of the underlying mechanisms of action demonstrated that cefminox inhibits the protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway through up-regulation of the expression of phosphatase and tensin homolog (PTEN, which is inhibited by GW9662), and enhances cyclic adenosine monophosphate (cAMP) production in PASMCs (which is inhibited by RO113842). In a rat model of hypoxia-induced pulmonary hypertension, cefminox displayed therapeutic efficacy not inferior to that of the prostacyclin analog iloprost or the PPARγ agonist rosiglitazone. Our results identified cefminox as a dual agonist of IP and PPARγ that significantly inhibits PASMC proliferation by up-regulation of PTEN and cAMP, suggesting that it has potential for treatment of PAH.

Molecular genetics and cellular events of K-Ras-driven tumorigenesis

Cellular transformation and the accumulation of genomic instability are the two key events required for tumorigenesis. K-Ras (Kirsten-rat sarcoma viral oncogene homolog) is a prominent oncogene that has been proven to drive tumorigenesis. K-Ras also modulates numerous genetic regulatory mechanisms and forms a large tumorigenesis network. In this review, we track the genetic aspects of K-Ras signaling networks and assemble the sequence of cellular events that constitute the tumorigenesis process, such as regulation of K-Ras expression (which is influenced by miRNA, small nucleolar RNA and lncRNA), activation of K-Ras (mutations), generation of reactive oxygen species (ROS), induction of DNA damage and apoptosis, induction of DNA damage repair pathways and ROS detoxification systems, cellular transformation after apoptosis by the blebbishield emergency program and the accumulation of genomic/chromosomal instability that leads to tumorigenesis.

Tumor suppressive protein phosphatases in human cancer: Emerging targets for therapeutic intervention and tumor stratification

Aberrant protein phosphorylation is one of the hallmarks of cancer cells, and in many cases a prerequisite to sustain tumor development and progression. Like protein kinases, protein phosphatases are key regulators of cell signaling. However, their contribution to aberrant signaling in cancer cells is overall less well appreciated, and therefore, their clinical potential remains largely unexploited. In this review, we provide an overview of tumor suppressive protein phosphatases in human cancer. Along their mechanisms of inactivation in defined cancer contexts, we give an overview of their functional roles in diverse signaling pathways that contribute to their tumor suppressive abilities. Finally, we discuss their emerging roles as predictive or prognostic markers, their potential as synthetic lethality targets, and the current feasibility of their reactivation with pharmacologic compounds as promising new cancer therapies. We conclude that their inclusion in clinical practice has obvious potential to significantly improve therapeutic outcome in various ways, and should now definitely be pushed forward.

High PTPN13 expression in high grade serous ovarian carcinoma is associated with a better patient outcome

Background

Chromosome 4q loss of heterozygosity (LOH) is frequently observed in high-grade serous ovarian carcinoma (HGSOC). However, this LOH has not been clearly associated with the inactivation of any tumor suppressor gene(s). As the tumor suppressor gene PTPN13 is located on chromosome 4q21, we investigated its expression in HGSOC.

Methods

PTPN13 protein expression was investigated by immunohistochemistry (IHC) in normal ovary epithelium and in 30 HGSOC samples, whereas PTPN13 mRNA expression was quantified by RT-PCR in another independent cohort of 28 HGSOC samples. Patients in both cohorts were followed for more than 8.5 years.

Results

PTPN13 protein expression was lower in one third of HGSOC samples compared with normal ovary epithelium. In both cohorts, high PTPN13 expression level (mRNA or protein) in the tumor was associated with favorable outcome and significantly longer survival (HR=0.27; p=0.0087 and HR=0.42; p=0.03, respectively).

Conclusion

This study demonstrates, for the first time, that high PTPN13 expression level is a prognostic indicator of favorable outcome in patients with HGSOC. This finding, in conjunction with our previous mechanistic studies, suggests that PTPN13 loss, possibly by 4q LOH, enhances HGSOC aggressiveness and highlight the interest of studying PTPN13 signaling in HGSOC to identify new potential therapeutic targets.

Genome-wide profiling of micro-RNA expression in gefitinib-resistant human lung adenocarcinoma using microarray for the identification of miR-149-5p modulation

To understand the mechanism involved in gefitinib resistance, we established gefitinib-resistant human HCC827/GR-8-1 cell line from the parental HCC827 cell line. We compared the micro-RNA expression profiles of the HCC827 cells HCC827/GR-8-1 using Agilent micro-RNA microarrays. The micro-RNAs, such as the miR-149-5p, were up- or downregulated and associated with acquired gefitinib resistance. Quantitative real-time polymerase chain reaction was then performed to verify the expression patterns of different micro-RNAs. The result showed that miR-149-5p was upregulated in the HCC827/GR-8-1 cell line. To investigate the biological function of miR-149-5p in non-small cell lung cancer cells acquired gefitinib resistance, we examined cell proliferation using a cell counting kit-8 assay. Cell viability was evaluated after the miR-149-5p mimics, inhibitors, and negative control were separately transfected into the non-small cell lung cancer cells. The results showed that the non-small cell lung cancer cells transfected with miR-149-5p mimics exhibited reduced cell motility. The drug-sensitivity assay results revealed that the overexpression of miR-149-5p effectively evaluates the half maximal inhibitory concentration values of the cell in response to gefitinib, and the downregulation of miR-149-5p can attenuate the half maximal inhibitory concentration values of the cell lines in response to gefitinib. Furthermore, the levels of miR-149-5p in the HCC827 and HCC827/GR-8-1 cells were inversely correlated with caspase-3 expression. In conclusion, this study revealed that miR-149-5p is upregulated in the HCC827/GR-8-1 cells and involved in the acquired gefitinib resistance.

MicroRNA-targeted therapeutics for lung cancer treatment

INTRODUCTION

Lung cancer is one of the leading causes of cancer-related mortality worldwide. MicroRNAs (miRNAs) are endogenous non-coding small RNAs that repress the expression of a broad array of target genes. Many efforts have been made to therapeutically target miRNAs in cancer treatments using miRNA mimics and miRNA antagonists. Areas covered: This article summarizes the recent findings with the role of miRNAs in lung cancer, and discusses the potential and challenges of developing miRNA-targeted therapeutics in this dreadful disease. Expert opinion: The development of miRNA-targeted therapeutics has become an important anti-cancer strategy. Results from both preclinical and clinical trials of microRNA replacement therapy have shown some promise in cancer treatment. However, some obstacles, including drug delivery, specificity, off-target effect, toxicity mediation, immunological activation and dosage determination should be addressed. Several delivery strategies have been employed, including naked oligonucleotides, liposomes, aptamer-conjugates, nanoparticles and viral vectors. However, delivery remains a main challenge in miRNA-targeting therapeutics. Furthermore, immune-related serious adverse events are also a concern, which indicates the complexity of miRNA-based therapy in clinical settings.