miR-143 suppresses the proliferation of NSCLC cells by inhibiting the epidermal growth factor receptor

The Role of miR-29a and miR-143 on the Anti-apoptotic MCL-1/cIAP-2 Genes Expression in EGFR Mutated Non-small Cell Lung Carcinoma Patients

The survival rate of lung cancer is low due to the high frequency of drug resistance in patients with mutations in the driver genes. Overexpression of anti-apoptotic genes is one of the most prominent features of tumor drug resistance. EGFR signaling induces the expression of anti-apoptotic genes. Also, microRNAs (miRNAs) have a critical role in regulating biological functions such as apoptosis; a process mostly eluded in cancer progression. The mutation screening was performed on one thousand non-small cell lung carcinoma patients to enroll clinical samples in this study. Bioinformatics analysis predicted that miRNAs (miR-29a, miR-143) might regulate MCL-1 and cIAP-2 expression. We investigated the expression of MCL-1, cIAP-2, miR-29a, and miR-143 encoding genes in adenocarcinoma patients with or without EGFR mutations before treatment. The potential role of miR-29a and miR-143 on gene expression was evaluated by overexpression and luciferase assays in HEK-293T cells. EGFR mutations were found in 262 patients (26.2%) with a greater incidence in females (36.23% vs. 20.37%, P = 0.001). The expression levels of MCL-1 and cIAP-2 genes in patients with mutated EGFR were higher than those of wild-type EGFR. In contrast, compared to those of patients with wild-type EGFR, the expression levels of miR-29a and miR-143 were lower in the patients carrying EGFR mutations. In cell culture, overexpression of miR-29a and miR-143 significantly downregulated the expression of MCL-1 and cIAP-2. Dual-luciferase reporter experiments confirmed that miR-29a and miR-143 target MCL-1 and cIAP-2 mRNAs, respectively. Our results suggest that upregulation of EGFR signaling in lung cancer cells may increase anti-apoptotic MCL-1 and cIAP-2 gene expression, possibly through downregulation of miR-29a-3p and miR-143-3p.

miR-381 Inhibits Proliferation and Invasion of Non-Small-Cell Cancer Cells by Targeting USP39

It is known that miR-381 plays a therapeutic role in a variety of cancers, but the regulatory mechanism of miR-381 in the treatment of lung cancer remains unclear. This study is aimed at exploring the expression level and mechanism of miR-381 in lung cancer. In this experiment, quantitative real-time PCR (qRT-PCR), western blot, and other methods were used to detect the expression of miR-381 and ubiquitin-specific protease 39 (USP39) in lung cancer tissues. The target genes of miR-381 were predicted by bioinformatics techniques, and the targeting relationship between miR-381 and USP39 was verified by the dual-luciferase reporting method. The expression levels of miR-381 and USP39 were adjusted to verify the effect of miR-381 on the expression of USP39 gene. The effect of miR-381 expression on proliferation of lung cancer cells was verified by cell proliferation and invasion experiments. miR-381 was downregulated in non-small-cell lung cancer tissues and cell lines, while USP39 was upregulated. The dual-luciferase reporter gene assay showed that miR-381 and USP39 had targeted binding sites. After transfection with miR-381 mimics, USP39 expression was significantly decreased, cell proliferation decreased, and apoptosis increased. After transfection with miR-381 inhibitor, USP39 expression was significantly increased, cell proliferation increased, and cell apoptosis decreased. Overexpression of USP39 significantly increased the invasion ability and cell survival curve (p < 0.05). In conclusion, overexpression of miR-381 can regulate the expression of USP39, inhibit the proliferation and invasion of cancer cells, and induce apoptosis of cancer cells. This may provide a new perspective and strategy for targeted therapy of non-small-cell lung cancer.

Synthetic Circular miR-21 Sponge as Tool for Lung Cancer Treatment

Lung cancer is the most common cancer in the world and several miRNAs are associated with it. MiRNA sponges are presented as tools to inhibit miRNAs. We designed a system to capture miRNAs based on circular RNAs (circRNA). To demonstrate its usefulness, we chose miR-21, which is upregulated and implicated in lung cancer. We constructed a miR-21 sponge and inserted it into a vector that facilitates circular RNA production (Circ-21) to study its effect on growth, colony formation, and migration in lung cancer cell lines and multicellular tumor spheroids (MTS). Circ-21 induced a significant and time-dependent decrease in the growth of A549 and LL2 cells, but not in L132 cells. Furthermore, A549 and LL2 cells transfected with Circ-21 showed a lower number of colonies and migration than L132. Similar findings were seen in A549 and LL2 Circ-21 MTS, which showed a significant decrease in volume growth, but not in L132 Circ-21 MTS. Based on this, the miR-21 circular sponge may suppress the processes of tumorigenesis and progression. Therefore, our system based on circular sponges seems to be effective, as a tool for the capture of other miRNAs.

Molecular Pathology of Lung Cancer

This overview of the molecular pathology of lung cancer includes a review of the most salient molecular alterations of the genome, transcriptome, and the epigenome. The insights provided by the growing use of next-generation sequencing (NGS) in lung cancer will be discussed, and interrelated concepts such as intertumor heterogeneity, intratumor heterogeneity, tumor mutational burden, and the advent of liquid biopsy will be explored. Moreover, this work describes how the evolving field of molecular pathology refines the understanding of different histologic phenotypes of non-small-cell lung cancer (NSCLC) and the underlying biology of small-cell lung cancer. This review will provide an appreciation for how ongoing scientific findings and technologic advances in molecular pathology are crucial for development of biomarkers, therapeutic agents, clinical trials, and ultimately improved patient care.

CircMMP11 overexpression predicts the poor survival of non-small cell lung cancer and downregulates miR-143 through methylation to suppress cell proliferation

Background

CircMMP11 is a characterized circRNA with oncogenic function in breast cancer. In this study, we explored the involvement of circMMP11 in non-small cell lung cancer (NSCLC).

Methods

Paired cancer and non-cancer tissues were collected from 66 NSCLC patients, and the expression of circMMP11 and miR-143 in these tissues were detected using RT-qPCRs. Overexpression levels of circMMP11 and miR-143 were performed by transfection, and their crosstalk was analyzed by RT-qPCRs. The effect of circMMP11 overexpression on miR-143 methylation was analyzed by methylation-specific PCR. CCK-8 assay was performed to analyze the roles of miR-143 and circMMP11 in regulating NSCLC cell proliferation.

Results

We found that circMMP11 was overexpressed in NSCLC and predicted patients’ poor survival. Moreover, a close correlation between circMMP11 and miR143 was observed. In NSCLC cells, circMMP11 overexpression reduced miR-143 expression and increased miR-143 methylation. CCK-8 assay analysis showed that miR-143 reversed the enhancing effects of circMMP11 overexpression on cell proliferation.

Conclusions

CircMMP11 is overexpressed in NSCLC and predicts poor survival. In addition, circMMP11 may downregulate miR-143 through methylation to suppress cell proliferation.

Novel MicroRNA Sponges to Specifically Modulate Gene Expression in Colon Cancer Cells

MicroRNA (miRNA) sponges allow the selective blockade of a complete family of associated miRNAs, which induce post-transcriptional gene silencing in their target through binding to 3'UTR mRNA. miRNA-365 and miRNA-145 are downregulated in colorectal cancer (CRC) but not in healthy tissues. Based on this, we constructed two vectors by inserting miRNA sponges (one for miRNA-365 and other for miRNA-145), and used enhanced green fluorescent protein (EGFP) as a 3'UTR reporter gene to analyze the ability of each sponge to catch its respective miRNA. Quantitative polymerase chain reaction (qPCR) results corroborated that the expression levels of both miRNAs were lower in CRC cell lines than in normal colon cell lines. Flow cytometry analysis revealed a decrease of the EGFP expression levels in the cell lines transfected with both sponges, being higher on the normal cell line while CRC cell lines presented a minimal decline. Also, this decrease was inversely proportional to the levels of expression of both miRNAs obtained by qPCR. These results were corroborated by fluorescence microscopy, showing a similar decrease in fluorescence. We propose a new vector system to carry in a specific way the expression of genes to CRC cells without affecting healthy cells, preventing damage to healthy tissues.

MicroRNAs in non-small cell lung cancer: Gene regulation, impact on cancer cellular processes, and therapeutic potential

Lung cancer remains the most lethal cancer among men and women in the United States and worldwide. The majority of lung cancer cases are classified as non-small cell lung cancer (NSCLC). Developing new therapeutics on the basis of better understanding of NSCLC biology is critical to improve the treatment of NSCLC. MicroRNAs (miRNAs or miRs) are a superfamily of genome-derived, small noncoding RNAs that govern posttranscriptional gene expression in cells. Functional miRNAs are commonly dysregulated in NSCLC, caused by genomic deletion, methylation, or altered processing, which may lead to the changes of many cancer-related pathways and processes, such as growth and death signaling, metabolism, angiogenesis, cell cycle, and epithelial to mesenchymal transition, as well as sensitivity to current therapies. With the understanding of miRNA biology in NSCLC, there are growing interests in developing new therapeutic strategies, namely restoration of tumor suppressive miRNAs and inhibition of tumor promotive miRNAs, to combat against NSCLC. In this article, we provide an overview on the molecular features of NSCLC and current treatment options with a focus on pharmacotherapy and personalized medicine. By illustrating the roles of miRNAs in the control of NSCLC tumorigenesis and progression, we highlight the latest efforts in assessing miRNA-based therapies in animal models and discuss some critical challenges in developing RNA therapeutics.

Deregulation of SATB2 in carcinogenesis with emphasis on miRNA-mediated control

The special AT-rich DNA binding protein (SATB2) is a nuclear matrix-associated protein and an important transcription factor for biological development, gene regulation and chromatin remodeling. Aberrant regulation of SATB2 has been found to highly correlate with various types of cancers including lung, colon, prostate, breast, gastric and liver. Recent studies have revealed that a subset of small non-coding RNAs, termed microRNAs (miRNAs), are important regulators of SATB2 function. As post-transcriptional regulators, miRNAs have been found to have fundament importance maintaining normal cellular development. Evidence suggests that multiple miRNAs, including miR-31, miR-34, miR-182, miR-211, miR-599, are capable of regulating SATB2 in cancers of the lung, liver, colon and breast. This review examines the molecular functions of SATB2 and miRNAs in the text of cancer development and potential strategies for cancer therapy with a focus on systemic miRNA delivery.

Downregulation of miR-33b promotes non-small cell lung cancer cell growth through reprogramming glucose metabolism miR-33b regulates non-small cell lung cancer cell growth

Glucose metabolism is a common target for cancer regulation and microRNAs (miRNAs) are important regulators of this process. Here we aim to investigate a tumor-suppressing miRNA, miR-33b, in regulating the glucose metabolism of non-small cell lung cancer (NSCLC). In our study, quantitative real-time polymerase chain reaction (qRT-PCR) showed that miR-33b was downregulated in NSCLC tissues and cell lines, which was correlated with increased cell proliferation and colony formation. Overexpression of miR-33b through miR-33b mimics transfection suppressed NSCLC proliferation, colony formation, and induced cell-cycle arrest and apoptosis. Meanwhile, miR-33b overexpression inhibited glucose metabolism in NSCLC cells. Luciferase reporter assay confirmed that miR-33b directly binds to the 3'-untranslated region of lactate dehydrogenase A (LDHA). qRT-PCR and Western blot analysis showed that miR-33b downregulated the expression of LDHA. Moreover, introducing LDHA mRNA into cells over-expressing miR-33b attenuated the inhibitory effect of miR-33b on the growth and glucose metabolism in NSCLC cells. Taken together, these results confirm that miR-33b is an anti-oncogenic miRNA, which inhibits NSCLC cell growth by targeting LDHA through reprogramming glucose metabolism.

Overexpression of miR-758 inhibited proliferation, migration, invasion, and promoted apoptosis of non-small cell lung cancer cells by negatively regulating HMGB

Non-small cell lung cancer (NSCLC) is one of the most fatal types of cancer with significant mortality and morbidity worldwide. MicroRNAs (miRs) have been confirmed to have positive functions in NSCLC. In the present study, we try to explore the role of miR-758 in proliferation, migration, invasion, and apoptosis of NSCLC cells by regulating high-mobility group box (HMGB) 3 (HMGB3.) NSCLC and adjacent tissues were collected. Reverse transcription quantitative PCR (RT-qPCR) was employed to detect expression of miR-758 and HMGB3 in NSCLC and adjacent tissues, in BEAS-2B cells and NSCLC cell lines. The targetted relationship between miR-758 and HMGB3 was identified by dual luciferase reporter gene assay. The effects of miR-758 on proliferation, migration, invasion, cell cycle, and apoptosis of A549 cells. MiR-758 expression was lower in NSCLC tissues, which was opposite to HMGB3 expression. The results also demonstrated that miR-758 can target HMGB3. The cells transfected with miR-758 mimic had decreased HMGB3 expression, proliferation, migration, and invasion, with more arrested cells in G₁ phase and increased apoptosis. Our results supported that the overexpression of miR-758 inhibits proliferation, migration, and invasion, and promotes apoptosis of NSCLC cells by negative regulating HMGB2. The present study may provide a novel target for NSCLC treatment.

MicroRNA-143-3p inhibits colorectal cancer metastases by targeting ITGA6 and ASAP3

MicroRNAs, which regulate mRNAs, operate through a variety of signaling pathways to participate in the development of colorectal cancer (CRC). In this study, we found that microRNA (miR)‐143‐3p expression was significantly lower in both CRC and liver metastatic CRC tissues from liver compared with normal colonic tissues. Functional assays showed that miR‐143‐3p inhibited CRC cell invasion and migration in vitro. Using a bioinformatics approach, we identified miR‐143‐3p target mRNAs. Among the candidate targets, only the expression of integrin alpha 6 (ITGA6) and ArfGAP with the SH3 domain and ankyrin repeat and PH domain 3 (ASAP3) were significantly reduced by miR‐143‐3p mimics as examined by western blot, and the metastasis potential of CRC cells was attenuated by endogenous ITGA6 and ASAP3 knockdown, determined by migration and invasion assays. Both ITGA6 and ASAP3 were upregulated in CRC tissues compared to normal tissues. Analysis of the relationship between clinicopathological features and ITGA6/ASAP3 protein expression in 200 patients with CRC showed a significant difference in positive ITGA6 expression between the early stage (I + II) and the advanced stage (III + IV), and ASAP3 expression levels positively correlated with metastasis in the lymph nodes. These results indicate that miR‐143‐3p acts as an anti‐oncogene by downregulating ITGA6/ASAP3 protein expression and could offer new insight into potential therapeutic targets for CRC.

MicroRNA-32 Regulates Development and Progression of Hepatocellular Carcinoma by Targeting ADAMTS9 and Affects Its Prognosis

Background

MicroRNA-32 (miR-32) induces cell proliferation and metastasis in hepatocellular carcinoma (HCC), but the detailed mechanisms of miR-32 in regulating oncogenesis and development of HCC have not been clarified. The aim of this study was to investigate the effects of miR-32 on HCC and its clinical pathological significance, as well as to determine the functional connection between miR-32 and ADAMTS9 in HCC.

Material/Methods

Quantitative RT-PCR was used to assess the expression levels of miR-32 in HCC tissues, adjacent non-cancerous tissues, and liver cancer cell lines. In vitro cell proliferation, migration, and invasion assays were performed to confirm the biological functions of miR-32. Quantitative RT-PCR, Western blot analysis, and luciferase reporter assays were used to evaluate the role of miR-32 in the regulation of ADAMTS9.

Results

miR-32 was highly expressed in HCC tissues compared with corresponding adjacent non-cancerous tissues. Over-expression of miR-32 was also found in 3 human liver cancer cell lines: SMMC-7721, Huh7, and HepG2. Moreover, increasing expression of miR-32 in HCC tissues was related to shorter overall survival. In vitro over-expression of miR-32 promoted cell proliferation, migration, and invasion; however, the under-expression of miR-32 revealed the opposite effects. Dual-luciferase reporter assay indicated that miR-32 can directly bind to the 3′-UTR of ADAMTS9. Western blot analysis showed that over-expression of miR-32 decreased expression of ADAMTS9 protein. Rescue tests further verified the connection between miR-32 and ADAMTS9.

Conclusions

Our data indicate that miR-32 accelerates progression in HCC by targeting ADAMTS9, and the abnormal expression of miR-32 is correlated with prognosis and could become a potential therapeutic target.

miR-143 Regulates Memory T Cell Differentiation by Reprogramming T Cell Metabolism

MicroRNAs are an important regulator for T cell immune response. In this study, we aimed to identify microRNAs with the potential to regulate T cell differentiation. The influence of miR-143 on differentiation and function of CD8+ T cells from healthy donors were detected, and it was found that miR-143 overexpression could significantly increase the differentiation of central memory T (Tcm) CD8+ cells, decrease cell apoptosis, and increase proinflammatory cytokine secretion. Furthermore, the specific killing of HER2-CAR T cells against esophageal cancer cell line TE-7 was enhanced by miR-143 overexpression. Glucose transporter 1 (Glut-1) was identified as the critical target gene of miR-143 in the role of T cell regulation. By inhibition Glut-1, miR-143 inhibited glucose uptake and glycolysis in T cell to regulated T cell differentiation. Tcm cell populations were also suppressed in parallel with the downregulation of miR-143 in tumor tissues from 13 patients with esophagus cancer. IDO and its metabolite kynurenine in the tumor microenvironment were screened as an upstream regulator of miR-143. IDO small interfering RNA significantly increased the expression of miR-143 and Tcm cell population. In conclusion, our results show that miR-143 enhanced antitumor effects of T cell by promoting memory T cell differentiation and metabolism reprogramming through Glut-1. Our findings will encourage the development of new strategies targeting miR-143 in both cancer cells and T cells.

Study of miR-143 expression in stomach cancer

The present study was planned to investigate miR-143 expression during stomach cancer. The study explored the relationship between miR-143 expression and clinicopathological characteristics including proliferation, migration and apoptosis of stomach cancer cells. Sixty-three samples from each of stomach cancer tissue and surrounding tissue were obtained. Total RNA was extracted. The expression levels of miR-143 from stomach cancer tissue as well as from surrounding tissue were measured by semi-quantitative PCR. The effects of miR-143 overexpression on the migration of stomach cancer cells were examined by Transwell assay. The effects of miR-143 overexpression on the apoptosis of stomach cancer cells were examined by flow cytometer. The expression level of miR-143 was significantly decreased in stomach cancer tissues in comparison to surrounding tissues (P<0.01). Moreover, the expression of miR-143 related well with the tumor size, TNM stage, lymphatic metastasis and relapse (P<0.01). On the other hand, stomach cancer cell line with overexpression of miR-143, showed significant decline in proliferation rate and migration rate comparison to control cells (P<0.01). However, it showed significant higher in apoptosis rate (P<0.01). The present study concluded that expression of miR-143 is low during stomach cancer. Further, higher expression levels of miR-143 have the ability to decline proliferation and migration of stomach cancer cells. In this manner, the expression level of miR-143 could be used as an important factor to determine the severity of stomach cancer.

A gender specific improved survival related to stromal miR-143 and miR-145 expression in non-small cell lung cancer

Micro RNAs (miRNA) are small non-coding RNAs that post-transcriptionally regulate gene expression. Dysregulation of miRNA cluster 143/145 has been reported in several malignancies, but their role in non-small cell lung cancer (NSCLC) remains elusive. This study investigates the prognostic impact of miR-143 and miR-145 in primary tumors and metastatic lymph nodes in NSCLC tissue. Tissue from 553 primary tumors and 143 matched metastatic lymph nodes were collected and tissue microarrays were constructed. In situ hybridization was used to evaluate miR-143 and miR-145 expression in tumor epithelial cells and stromal cells in the primary tumors and lymph nodes. In vivo data was supplemented with functional studies of cell lines in vitro to evaluate the role of miR-143 and miR-145 in NSCLC tumorigenesis. In our cohort, stromal miR-143 (S-miR-143) and miR-145 (S-miR-145) expression in primary tumor tissue were independent prognosticators of improved disease-specific survival (DSS) in female (S-miR-143, HR: 0.53, p = 0.019) and male patients (S-miR-145, HR: 0.58, p = 0.021), respectively. Interesting correlations between the miR cluster 143/145 and previously investigated steroid hormone receptors from the same cohort were identified, substantiating their gender dependent significance.

The mechanism of miR-143 inducing apoptosis of liver carcinoma cells through regulation of the NF-κB pathway

Primary hepatic carcinoma is a common malignant tumor with poor treatment efficacy. The effect and mechanism of miR-143 in apoptosis of liver carcinoma cells were investigated in the present study. In vitro transfection of liver carcinoma SMMC-7721 cells was performed using artificially synthesized miR-143 mimics. The proliferation of liver carcinoma cells that were treated was detected by MTT assay. Liver carcinoma cells were then stained using the Annexin V-FITC/PI method, and the apoptosis of stained liver carcinoma cells was measured using a flow cytometer. The relative mRNA expression of NF-κB p65 in the intervention and control groups was assayed using reverse transcription-quantitative polymerase chain reaction, and the protein expression of NF-κB p65 was detected using western blot analysis. The results showed that, in the intervention group, the proliferation rate of cells transfected using miR-143 mimics was significantly lower than that in the control group, the number of apoptotic SMMC-7721 cells in the intervention group increased, and the protein expression of NF-κB p65 was decreased. Thus, miR-143 may downregulate the protein expression of NF-κB p65, thereby triggering the NF-κB signaling transduction pathway inducing apoptosis of liver carcinoma cells.

The association of polymorphisms in miRNAs with nonsmall cell lung cancer in a Han Chinese population

Background

MicroRNAs (miRNAs) have been demonstrated to play important roles in cancer progression. Recently, studies have revealed that polymorphisms in miRNAs might be associated with cancer susceptibility.

Materials and methods

In the current study, we investigated the associations of single nucleotide polymorphisms (SNPs) in miRNAs (rs11134527 in pri-miR-218-2, rs74693964 in pri-miR-145, rs6062251 in pri-miR-133a-2, and rs4705343 in pri-miR-143) with nonsmall cell lung cancer (NSCLC) in a Han population from Yunnan Province, Southwest China using a binary logistic regression analysis. A total of 452 patients with NSCLC and 452 healthy individuals were recruited for polymorphism genotyping using the TaqMan assay.

Results

Our results showed that the allelic frequencies of rs11134527 and rs4705343 were significantly different between the NSCLC and control groups (P=0.025 and 0.029). Additionally, the genotypic frequencies of rs11134527 were significantly different between the NSCLC and control groups (P=0.045). The mode of inheritance analysis showed that genotypes A/G+G/G of rs11134527 were associated with a lower risk of NSCLC under the dominant model (OR=0.69; 95% CI: 0.51–0.94). In addition, genotypes 2C/C+C/T of rs4705343 were associated with an increased risk of NSCLC under the log-additive model (OR=1.25; 95% CI: 1.01–1.53). However, there was no significant difference in the other SNPs between the NSCLC and control groups (P>0.05). Moreover, the association analysis of these SNPs between adenocarcinoma and squamous cell carcinoma (SCC) showed that allele A of rs11134527 was associated with SCC (OR=0.65; 95% CI: 0.48–0.88).

Conclusion

Our results indicated that the A allele of rs11134527 might be a risk factor (OR=1.24; 95% CI: 1.03–1.50) and that the T allele of rs4705343 might be a protective factor (OR=0.80; 95% CI: 0.66–0.98) for NSCLC in a Han Chinese population.

miR-25 enhances cell migration and invasion in non-small-cell lung cancer cells via ERK signaling pathway by inhibiting KLF4

In recent years, microRNAs (miRNAs/miRs) have gained increasing interest in cancer research. Increasing evidences demonstrated that miRNAs are important for tumor early detection and prognosis. The present study aimed to explore the function of miR-25 in non-small-cell lung cancer (NSCLC) and its underlying mechanisms. The expression levels of miR-25 and Krüppel-like factor 4 (KLF4) were assessed in 31 pairs of tissue from patients with NSCLC. In addition, the biological roles of miR-25 in NSCLC were analyzed via a cell wound healing assay, Transwell invasion and migration assays. Target genes of miR-25 were predicted using TargetScan and verified via a dual luciferase activity assay, western blotting and reverse transcription-quantitative polymerase chain reaction. The downstream signaling pathway was confirmed by western blot analysis. In the present study, miR-25 was overexpressed in 31 NSCLC samples compared with in corresponding normal tissues. Overexpression of miR-25 using miR-25 mimics markedly promoted NSCLC cell migration and invasion, while inhibition of miR-25 exerted the opposite effect. KLF4 was suggested to be a novel target gene of miR-25 in NSCLC cells. Knockdown of KLF4 promoted the migration and invasion of NSCLC cells, whereas rescue of KLF4 expression reduced cell motion ability in miR-25-overexpressing NSCLC cells. Furthermore, it was demonstrated that miR-25 activated the extracellular signal-regulated kinase (ERK) signaling pathway, which eventually led to increased vimentin, matrix metalloproteinase 11 and N-cadherin levels, and the downregulation of E-cadherin expression by inhibiting the expression of KLF4. In conclusion, miR-25 was demonstrated to activate the ERK signaling pathway by directly targeting KLF4, promoting cell migration and invasion. The findings of the present study indicated that miR-25 or KLF4 may serve as a therapeutic target for the treatment of NSCLC.

MicroRNAs associated with therapy of non-small cell lung cancer

Background & Objective: The incidence of non-small cell lung cancer (NSCLC) has been rising over the past several decades. Despite various therapeutic regimens and modern diagnostic techniques are developed, NSCLC still have an extremely poor prognosis due to drug resistance. Therefore, it is critical to find a novel precise diagnosis and effective treatment approach for NSCLC patients. MicroRNAs (MiRNAs) are a class of 18-25nt non-coding small RNAs, which have been shown to be involved profoundly in the pathogenesis such as cellular proliferation, differentiation, development, apoptosis and tumorigenesis in many human tumors including of NSCLC. We reviewed existing research literature regarding correlations between miRNAs and their target's response to anticancer treatment, and summarized the recent findings between miRNAs and therapy availability in NSCLC.

miR-143 Inhibits Cell Proliferation of Gastric Cancer Cells Through Targeting GATA6

Recent studies have suggested that the dysregulation of microRNAs (miRNAs) plays a critical role in the progression of human cancers, including gastric cancer (GC). miR-143 had been reported to function as a tumor suppressor in GC. However, the exact molecular mechanism of how miR-143 participates in GC progression remains to be determined. In this present study, we revealed that the expression of miR-143 was significantly downregulated in human GC tissues and cell lines compared with normal tissues and a normal gastric epithelium cell line. In addition, upregulation of the expression of miR-143 in a GC cell line inhibited cell proliferation and induced cell cycle arrested in the G0/G1 phase. Furthermore, GATA6 was identified as a direct target of miR-143 in GC using the luciferase reporter assay. Upregulation of miR-143 inhibited the expression of GATA6 in GC cell lines. Moreover, the overexpression of GATA6 could attenuate the effect of miR-143 on cell proliferation in the GC cell lines. Collectively, these data indicated that miR-143 plays a tumor suppressor role partly through regulating the expression of GATA6 in GC. Therefore, targeting miR-143 may be a novel therapeutic method for GC.

The miR-875-5p inhibits SATB2 to promote the invasion of lung cancer cells

The pathogenesis of non-small cell lung cancer (NSCLC) is regulated by various miRNAs. In this study, we identified that miR-875-5pis up-regulated in NSCLC patients, and inhibited SATB Homeobox 2(SATB2) to promote proliferation and invasion of NSCLCcells.CCK-8assay revealed thatmiR-875-5p mimics promoted proliferation of NSCLC cells. Transwell assay showed that miR-875-5pmimicspromoted the invasion and migration of NSCLC cells. Luciferase assays confirmed that miR-875-5pdirectly binds to the 3'untranslated region of SATB2, and western blotting showed that miR-875-5psuppresses the expression of SATB2 at the protein level. Moreover, the inhibitors of miR-875-5pinhibit proliferation and invasion of NSCLC cell lines. The miR-875-5pwouldbe a potential therapeutic target for NSCLC treatment in the future.

MicroRNA-34a/EGFR axis plays pivotal roles in lung tumorigenesis

MicroRNAs (miRNAs) are vital in the regulation of tumor progression and invasion. Dysregulation of miRNAs has been linked to the development of various types of human cancers, including non-small-cell lung cancer (NSCLC). However, the effect of miRNA-34a (miR-34a), a key regulator of tumor suppression, on the tumorigenesis of NSCLC has not been fully elaborated. Herein, we reveal that miR-34a is significantly downregulated in NSCLC tissues and cell lines, suggesting that miR-34a might function as a tumor suppressor in lung cancer. We also confirmed that epidermal growth factor receptor (EGFR) is a direct target of miR-34a, and our data reveal that siRNA knockdown of EGFR can inhibit cell proliferation, promote apoptosis and arrest cell-cycle progression. In addition, EGFR can reverse the suppressive function of miR-34a overexpression on proliferation and cell apoptosis. Furthermore, in vivo experiments demonstrated that miR-34a suppress tumor growth, both in the A549 xenograft model, as well as in the metastatic tumors in nude mice. Taken together, our findings suggest that miR-34a inhibits NSCLC tumor growth and metastasis through targeting EGFR.