Bovine enhancer-regulated circSGCB acts as a ceRNA to regulate skeletal muscle development via enhancing KLF3 expression

Skeletal muscle growth and development in livestock and poultry play a pivotal role in determining the quality and yield of meat production. However, the mechanisms of myogenesis are remained unclear due to it finely regulated by a complex network of biological macromolecules. In this study, leveraging previous sequencing data, we investigated a differentially expressed circular RNA (circSGCB) present in fetal and adult muscle tissues among various ruminant species, including cattle, goat, and sheep. Our analysis revealed that circSGCB is a single exon circRNA, potentially regulated by an adjacent bovine enhancer. Functional analysis through loss-of-function tests demonstrated that circSGCB exerts inhibitory effects on bovine myoblast proliferation while promoting myocytes generation. Furthermore, we discovered that circSGCB primarily localizes to the cytoplasm, where it functions as a molecular sponge by binding to bta-miR-27a-3p. This interaction releases the mRNAs of KLF3 gene and further activates downstream functional pathways. In vivo, studies provided evidence that up-regulation of KLF3 contributes to muscle regeneration. These findings collectively suggest that circSGCB operates via a competing endogenous RNA (ceRNA) mechanism to regulate KLF3, thereby influencing myogenesis in ruminants and highlights it may as potential molecular targets for enhancing meat production in livestock and poultry industries.

KLF3 promotes colorectal cancer growth by activating WNT1

OBJECTIVE

The function of Kruppel-like factor 3 (KLF3) remains largely unexplored in colorectal cancer (CRC).

METHODS

KLF3 expression in CRC was assessed through qPCR, western blotting, immunohistochemical assays, and The Cancer Genome Atlas (TCGA) database. The tumor-promoting capacity of KLF3 was explored by performing in vitro functional experiments using CRC cells. A subcutaneous nude mouse tumor assay was employed to evaluate tumor growth. To further elucidate the interaction between KLF3 and other factors, luciferase reporter assay, agarose gel electrophoresis, and ChIP analysis were performed.

RESULTS

KLF3 was downregulated in CRC tissue and cells. Silencing of KLF3 increased the potential of CRC cells for proliferation, migration, and invasion, while its activation decreased these processes. Downregulated KLF3 was associated with accelerated tumor growth in vivo. Mechanistically, KLF3 was discovered to target the promoter sequence of WNT1. Consequently, the diminished expression of KLF3 led to the buildup of WNT1 and the WNT/β-catenin pathway activation, consequently stimulating the progression of CRC.

CONCLUSIONS

This investigation suggests that the involvement of KLF3/WNT1 regulatory pathway contributes to the progression of CRC, thereby emphasizing its promise as an important focus for future therapies aimed at treating CRC.

Pan-cancer analysis of Krüppel-like factor 3 and its carcinogenesis in pancreatic cancer

Background

Krüppel-like factor 3 (KLF3) is a key transcriptional repressor, which is involved in various biological functions such as lipogenesis, erythropoiesis, and B cell development, and has become one of the current research hotspots. However, the role of KLF3 in the pan-cancer and tumor microenvironment remains unclear.

Methods

TCGA and GTEx databases were used to evaluate the expression difference of KLF3 in pan-cancer and normal tissues. The cBioPortal database and the GSCALite platform analyzed the genetic variation and methylation modification of KLF3. The prognostic role of KLF3 in pan-cancer was identified using Cox regression and Kaplan-Meier analysis. Correlation analysis was used to explore the relationship between KLF3 expression and tumor mutation burden, microsatellite instability, and immune-related genes. The relationship between KLF3 expression and tumor immune microenvironment was calculated by ESTIMATE, EPIC, and MCPCOUNTER algorithms. TISCH and CancerSEA databases analyzed the expression distribution and function of KLF3 in the tumor microenvironment. TIDE, GDSC, and CTRP databases evaluated KLF3-predicted immunotherapy response and sensitivity to small molecule drugs. Finally, we analyzed the role of KLF3 in pancreatic cancer by in vivo and in vitro experiments.

Results

KLF3 was abnormally expressed in a variety of tumors, which could effectively predict the prognosis of patients, and it was most obvious in pancreatic cancer. Further experiments verified that silencing KLF3 expression inhibited pancreatic cancer progression. Functional analysis and gene set enrichment analysis found that KLF3 was involved in various immune-related pathways and tumor progression-related pathways. In addition, based on single-cell sequencing analysis, it was found that KLF3 was mainly expressed in CD4Tconv, CD8T, monocytes/macrophages, endothelial cells, and malignant cells in most of the tumor microenvironment. Finally, we assessed the value of KLF3 in predicting response to immunotherapy and predicted a series of sensitive drugs targeting KLF3.

Conclusion

The role of KLF3 in the tumor microenvironment of various types of tumors cannot be underestimated, and it has significant potential as a biomarker for predicting the response to immunotherapy. In particular, it plays an important role in the progression of pancreatic cancer.

KLF3 Transcription Activates WNT1 and Promotes the Growth and Metastasis of Gastric Cancer via Activation of the WNT/β-Catenin Signaling Pathway

The transcription factor Krüppel-like factor (KLF) 3 is one of the members of the KLF family, which plays an important role in tumor progression. Nevertheless, the role of KLF3 in the growth and metastasis of gastric cancer (GC) still needs to be elucidated. Bioinformatics analysis showed that KLF3 was overexpressed in patients with GC, and the high expression of KLF3 was correlated with poor survival. KLF3 was also overexpressed in GC clinical samples and cell lines. In vitro functional role of KLF3 in GC cells was explored by a gain-of-function and loss-of-function assay. Overexpressed KLF3 promoted the cell proliferation, migration, invasion, and epithelial-mesenchymal transition of GC cells, whereas suppressed KLF3 inhibited these biological behaviors. The clinical samples and bioinformatics analysis showed that WNT1 was also highly expressed in GC tumor tissues and positively correlated with KLF3 expression. The luciferase reporter assay and chromatin immunoprecipitation result confirmed that KLF3 could directly bind to the WNT1 promoter to increase the transcriptional activity of WNT1, thus regulating its expression. Overexpressed KLF3 enhanced the protein expression level of p-GSK3β(Ser9) and β-catenin, the key elements in the WNT/β-catenin signaling pathway. Repression of KLF3 decreased the level of p-GSK3β(Ser9) and β-catenin. Immunofluorescence images showed that KLF3 promoted nuclear β-catenin accumulation. Inhibition of WNT1 attenuated the proliferation, migration, and invasiveness of KLF3-overexpressing GC cells. Moreover, the xenograft mouse model confirmed that KLF3 promotes GC tumor growth and metastasis in vivo. Our results demonstrated that KLF3 activates the WNT/β-catenin signaling pathway via WNT1 to promote GC tumor growth and metastasis, indicating that repression of KLF3 may act as a potential therapeutic target for patients with GC.

Fat mass and obesity associated (FTO)-mediated N6-methyladenosine modification of Krüppel-like factor 3 (KLF3) promotes osteosarcoma progression

N6-methyladenosine (m6A) methylation is the most common and abundant methylation modification of eukaryotic mRNAs, which is involved in tumor initiation and progression. The study aims to explore the potential role and the regulatory mechanism of fat mass and obesity associated (FTO) in osteosarcoma (OS) progression. In this study, we detected the expressions of Krüppel-like factor 3 (KLF3) in OS cells and tissues and found that the mRNA and protein levels of KLF3 were increased in OS cells and tissues and significantly related to tumor size, metastasis, and TNM stage and poor prognosis of OS patients. FTO promoted the proliferation and invasion and suppressed apoptosis of OS cells through cell experiments in vitro. Further mechanism dissection revealed that FTO and YTHDF2 enforced the decay of KLF3 mRNA and decreased its expression. FTO-mediated mRNA demethylation inhibited KLF3 expression in the YTHDF2-dependent manner. Moreover, KLF3 overexpression abrogated FTO-induced oncogenic effects on the proliferation and invasion of OS cells. Overall, our findings showed that FTO-mediated m6A modification of KLF3 promoted OS progression, which may provide a therapeutic target for OS.

Inhibition of the cell migration, invasion and chemoresistance of colorectal cancer cells through targeting KLF3 by miR-365a-3p

Background: Metastasis and chemoresistance limit treatment efficacy of colorectal cancer (CRC) patients. MicroRNAs (miRNAs) have been believed to be candidate biomarkers for tumor cell proliferation, metastasis and chemoresistance, but the related molecular mechanisms are not clear for prognosis prediction.

Aims: We aimed to investigate the role of miR-365a-3p in metastasis and chemoresistance of CRC.

Methods: The expression levels of miR-365a-3p in clinical CRC tissues were analyzed. The effects of miR-365a-3p expression levels on tumor chemoresistance, invasion and migration were also determined. A dual luciferase reporter gene assay was used to determine the effect of miR-365a-3p on its target gene, Kruppel-like factor 3 (KLF3), and the effect of the miR-365a-3p/KLF3 axis on CRC cell chemoresistance, migration and invasion was further investigated.

Results: In patients with CRC with lymph node or distant organ metastasis or in CRC cell lines, the expression levels of miR-365a-3p were significantly downregulated. In addition, the findings of Transwell assays demonstrated that miR-365a-3p significantly suppressed CRC cell migration and invasion. The dual luciferase reporter gene assay results suggested that miR-365a-3p may play an important role in the regulation of migration, invasion and chemoresistance in CRC cells.

Conclusions: The findings of present study provided evidence to suggest that miR-365a-3p may be a potential tumor suppressor gene in CRC and may inhibit the migration, invasion and chemoresistance of CRC cells. These results suggested that targeting miR-365a-3p/KLF3 axis may represent a potential therapeutic intervention for metastatic disease in patients with CRC.

Overexpression of Krueppel like factor 3 promotes subcutaneous adipocytes differentiation in goat Capra hircus

Previous research reported that KLF3 plays different roles in the regulation of adipose deposition across species. However, the exact function of KLF3 in goat subcutaneous adipocyte remains unknown. Here, the goat KLF3 gene was firstly cloned and showed that the mRNA sequence of the goat KLF3 gene was 1,264 bp (GenBank accession number: KU041753.1) and its coding sequence was 1,037 bp, encoding 345 amino acids with three classic zinc finger domains of KLFs family at its C-terminus. The alignment of the amino acid sequence of KLF3 among various species demonstrated that goat had the highest homology to that of sheep, presenting 99.4% similarity, while the homology similarity to that of mice presented only 93.62% in contrast. Furthermore, KLF3 had highest mRNA level in fat tissue and lowest level in the heart in comparison. Additionally, the mRNA level of KLF3 gradually tended to increase during adipogenesis. Interestingly, overexpression of KLF3 increased lipid accumulation. In line with this, the gain-of-function of KLF3 dramatically elevated the mRNA levels of TG synthetic genes and adipogenic maker genes (p < .01) . Moreover, overexpression of KLF3 upregulated all the potential target genes, except for C/EBPα. These results suggested that KLF3 is a positive regulator for subcutaneous adipocyte differentiation in goats.

Garcinia cambogia attenuates adipogenesis by affecting CEBPB and SQSTM1/p62-mediated selective autophagic degradation of KLF3 through RPS6KA1 and STAT3 suppression

The overexpansion of adipose tissues leads to obesity and eventually results in metabolic disorders. Garcinia cambogia (G. cambogia) has been used as an antiobesity supplement. However, the molecular mechanisms underlying the effects of G. cambogia on cellular processes have yet to be fully understood. Here, we discovered that G. cambogia attenuated the expression of CEBPB (CCAAT/enhancer binding protein (C/EBP), beta), an important adipogenic factor, suppressing its transcription in differentiated cells. In addition, G. cambogia inhibited macroautophagic/autophagic flux by decreasing autophagy-related gene expression and autophagosome formation. Notably, G. cambogia markedly elevated the expression of KLF3 (Kruppel-like factor 3 (basic)), a negative regulator of adipogenesis, by reducing SQSTM1/p62-mediated selective autophagic degradation. Furthermore, increased KLF3 induced by G. cambogia interacted with CTBP2 (C-terminal binding protein 2) to form a transcriptional repressor complex and inhibited Cebpa and Pparg transcription. Importantly, we found that RPS6KA1 and STAT3 were involved in the G. cambogia-mediated regulation of CEBPB and autophagic flux. In an obese animal model, G. cambogia reduced high-fat diet (HFD)-induced obesity by suppressing epididymal and inguinal subcutaneous white adipose tissue mass and adipocyte size, which were attributed to the regulation of targets that had been consistently identified in vitro. These findings provide new insight into the mechanism of G. cambogia-mediated regulation of adipogenesis and suggest molecular links to therapeutic targets for the treatment of obesity.

miR-130a-Mediated KLF3 Can Inhibit the Growth of Lung Cancer Cells

Background

The role of microRNA (miR) in tumors has been reported in numerous articles. Previous studies have found that miR-130a is low expressed in lung cancer, but the related mechanism has not been fully elucidated. This study mainly explores the mechanism of miR-130a in lung cancer, so as to provide potential therapeutic targets for clinical applications.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of miR-130a and KLF3 in the tissues of lung cancer patients. The miR-130a-mimics and miR-130a-inhibit were constructed. Cell proliferation, invasion, migration and apoptosis were determined by CCK-8, transwell, scratch test and flow cytometry. Western Blot was used to determine the expression of KLF3 protein in cells, and the dual-luciferase reporter to determine the relationship between KLF3 and miR-130a.

Results

miR-130a shows low expression in NSCLC patients, while KLF3 shows high expression, exhibiting a negative correlation. The 5-year survival rate of patients with low miR-130a expression and high KLF3 expression was reduced. Cox regression analysis showed that miR-130a was an independent prognostic factor for NSCLC patients. The dual-luciferase reporter revealed that miR-130a bound to KLF3 in a targeted manner, and cell experiments showed that miR-130a could inhibit the growth of lung cancer cells by regulating the expression of KLF3.

Conclusion

miR-130a shows low expression in lung cancer and predicts a poor prognosis. In addition, up-regulation of miR-130a can down-regulate KLF3 and inhibit the growth of lung cancer.

miR-32-5p Regulates Lipid Accumulation in Intramuscular Fat of Erhualian Pigs by Suppressing KLF3

Intramuscular fat (IMF) and subcutaneous fat (SCF) are important traits affecting the economics of the pork industry, in which less SCF and more IMF content is desirable. However, the mechanisms that regulate IMF and SCF content are not clear yet. In this study, we demonstrate that KLF3 (Krüppel-like factor 3) was negatively correlated with IMF content in the longissimus dorsi muscle of Erhualian pigs. In addition, the expression level of KLF3 was significantly higher in IMF than SCF. Overexpression and knockdown experiments revealed that KLF3 could suppress adipocyte differentiation in vitro by downregulating adipogenic markers, including PPARG, C/EBPA, and FABP4. Luciferase activity analysis proved that miR-32-5p was able to suppress KLF3. Notably, miR-32-5p level was negatively correlated to KLF3 mRNA level in both IMF and SCF tissues. The same relationship was proved in samples with different IMF content. Further studies showed that miR-32-5p could promote adipocyte differentiation via inhibiting KLF3. Our results suggest that the miR-32-5p-KLF3 pathway is involved in the regulation of differential fat deposition of IMF and SCF tissues.

Circ_0084043 promotes cell proliferation and glycolysis but blocks cell apoptosis in melanoma via circ_0084043-miR-31-KLF3 axis

Melanoma is an aggressive malignant tumor. The crucial role of circular RNAs has been documented in many types of cancer, including melanoma. The objective of this study was to uncover the function of circ_0084043 in the biological process of melanoma and associated mechanism of action. The expression of circ_0084043, miR-31, and Krüppel-like factor 3 (KLF3) was determined by qRT-PCR. Cell proliferation and apoptosis were monitored by the MTT assay and flow cytometry assay, respectively. The progression of glycolysis was evaluated according to the levels of glucose consumption, lactate production, and ATP concentration using appropriate detection kits. The relationship between miR-31 and circ_0084043 or KLF3 was predicted by the bioinformatics tool and ascertained by the dual-luciferase reporter assay. The protein levels of KLF3 and glucose transporter 1 (Glut1) were quantified by western blot. A xenograft model was established to ascertain the role of circ_0084043 in vivo. As a result, circ_0084043 expression was reinforced in melanoma tissues and cells. Circ_0084043 knockdown inhibited cell proliferation, induced cell apoptosis, and restrained glycolysis. MiR-31 was a target of circ_0084043, and miR-31 deficiency reversed the role of circ_0084043 knockdown. KLF3 was targeted by miR-31, and KLF3 upregulation abolished the effects of miR-31 enrichment. Moreover, circ_0084043 knockdown impeded tumor growth in vivo and suppressed the level of Glut1 by modulating miR-31 and KLF3. Circ_0084043 promoted cell proliferation and glycolysis, and blocked apoptosis through the circ_0084043–miR-31–KLF3 regulatory axis in melanoma.

miR-324-5p Contributes to Cell Proliferation and Apoptosis in Pancreatic Cancer by Targeting KLF3

Pancreatic cancer cells are characterized by high cell proliferation and low cell apoptosis, but the factors involved in these processes remain to be further studied. In this study, we report that miR-324-5p regulates the proliferation and apoptosis of pancreatic cancer cells through regulating the expression of Krüppel-like factor 3 (KLF3). In both pancreatic cancer tissues and cell lines, the levels of miR-324-5p are significantly increased. Inhibition of miR-324-5p represses cell proliferation but promotes cell apoptosis, whereas overexpression of miR-324-5p exerts the opposite effect. Furthermore, we identified KLF3, a factor regulating pancreatic cancer cell proliferation and apoptosis, as a new direct downstream target of miR-324-5p. Our results suggest that miR-324-5p plays an important role in pancreatic cancer cell proliferation and apoptosis via downregulating the expression of KLF3.

Salvia miltiorrhiza-Derived Sal-miR-58 Induces Autophagy and Attenuates Inflammation in Vascular Smooth Muscle Cells

Autophagy is associated with the cytoprotection of physiological processes against inflammation and oxidative stress. Salvia miltiorrhiza possesses cardiovascular protective actions and has powerful anti-oxidative and anti-inflammatory effects; however, whether and how Salvia miltiorrhiza-derived microRNAs (miRNAs) protect vascular smooth muscle cells (VSMCs) by inducing autophagy across species are unknown. We first screened and identified Sal-miR-58 from Salvia miltiorrhiza as a natural autophagy inducer. Synthetic Sal-miR-58 suppresses chronic angiotensin II (Ang II) infusion-induced abdominal aortic aneurysm (AAA) formation in mice, as well as induces autophagy in VSMCs and attenuates the inflammatory response elicited by Ang II in vivo and in vitro. Mechanistically, Sal-miR-58 downregulates Krüppel-like factor 3 (KLF3) expression through direct binding to the 3' UTR of KLF3, which in turn relieves KLF3 repression of E3 ubiquitin ligase neural precursor cell-expressed developmentally downregulated 4-like (NEDD4L) expression, whereas NEDD4L upregulation increases the ubiquitination and degradation of the platelet isoform of phosphofructokinase (PFKP), subsequently leading to a decrease in the activation of Akt/mammalian target of rapamycin (mTOR) signaling and facilitating VSMC autophagy induced by Sal-miR-58 in the context of chronic Ang II stimulation and aneurysm formation. Our results provide the first evidence that plant-derived Sal-miR-58 induces autophagy and attenuates inflammation in VSMCs through cross-species modulation of the KLF3/NEDD4L/PFKP regulatory pathway.

miR-324-5p promotes adipocyte differentiation and lipid droplet accumulation by targeting Krueppel-like factor 3 (KLF3)

miRNAs, a kind of noncoding small RNA, play a significant role in adipose differentiation. In this study, we explored the effect of miR-324-5p in adipose differentiation, and found that miR-324-5p could promote adipocytes differentiation and increase body weight in mice. We overexpressed miR-324-5p during adipocytes differentiation, by oil red O and bodipy staining found that lipid accumulation was increased, and the expression level of adipogenic related genes were significantly increased. And the opposite experimental results were obtained after inhibiting miR-324-5p. In vivo, we injected miR-324-5p agomiR in obese mice and found that body weight, adipocyte area, and adipogenic-related gene expression level were significantly increased but lipolytic genes were decreased. To further explore the mechanism of miR-324-5p regulation in lipid accumulation, we constructed Krueppel-like factor 3 (KLF3) 3'-untranslated region luciferase reporter vector and KLF3 pcDNA 3.1 overexpression vector, and found that miR-324-5p was able to directly target KLF3. Overall, in this study we found that miR-324-5p could promote mice preadipoytes differentiation and increase mice fat accumulation by targeting KLF3.

[KLF3 regulates the movement, migration and invasion of breast cancer cells through STAT3]

Objective: To observe the effect of KLF3 on the expression of STAT3 in breast cancer cells, and to explore the potential mechanism of KLF3 affecting the movement, migration and invasion of breast cancer cells. Methods: Firstly, the expression of STAT3 was detected by Western blot, real-time fluorescent quantitative PCR, luciferase reporter system and chromatin immunoprecipitation in breast cancer cells. Secondly, the STAT3 promoter mutant was constructed. The plasmid further confirmed the effect of KLF3 on the activity of STAT3 promoter; the cell scratching test and Transwell method were used to detect the ability of cell movement, migration and invasion. Finally, animal experiments were conducted to verify the effect of knockdown of KLF3 on tumor metastasis in animals. Results: In breast cancer cells, knockdown of KLF3 promoted STAT3 protein expression. The mRNA level of STAT3 was increased by (3.58±0.65) fold after knockdown of KLF3 in MDA-MB-231 cells, while the mRNA level of STAT3 was increased by (2.28±0.19) fold after KLF3 knockdown in MCF-7 cells (P<0.001). KLF3 boundto the promoter region of STAT3. The transcriptional activity of STAT3 increased by (2.47±0.87) fold after knockdown of KLF3 in MDA-MB-231 cells, while the transcriptional activity of STAT3 increased by (2.63±0.65) fold after KLF3 knockdown in MCF-7 cells, P<0.01. KLF3 knockdown inhibitedthe movement,migrate and invade of breast cancer cells. Based on this, silence STAT3 partially reversed the function of KLF3. Knockdown of KLF3 promotedtumor metastasis in mice. Conclusions: KLF3 knockdown can promote the transcriptional activity of STAT3, which promotes the protein expression of the latter. KLF3 can affect the movement, migration and invasion of breast cancer cells through STAT3. KLF3 may be a potential target for the treatment of metastatic breast cancer.

KLF3 is a crucial regulator of metastasis by controlling STAT3 expression in lung cancer

Lung cancer is one of the most common causes of cancer‐related mortality worldwide, which is partially due to its metastasis. However, the mechanism underlying its metastasis remains elusive. In this study, we showed that a low Krüppel‐like factor 3 (KLF3) expression level is correlated with a poor prognosis and TNM stages in clinical patients with lung cancer and further demonstrated that KLF3 expression is downregulated in lung cancer tissues compared with adjacent normal samples. In addition, bioinformatics analysis results showed that KLF3 expression is related to lung cancer epithelial‐mesenchymal transition (EMT). In vitro and in vivo experiments also showed that KLF3 silencing promotes lung cancer EMT and enhances lung cancer metastasis. More importantly, bioinformatics analysis and in vitro experiments indicated that the role of KLF3 in lung cancer metastasis is dependent on the STAT3 signaling pathway. Overall, our data indicated the crucial function of KLF3 in lung cancer metastasis and suggested opportunities to improve the therapy of patients with lung cancer.

NEAT1/miR-23a-3p/KLF3: a novel regulatory axis in melanoma cancer progression

BACKGROUND

Melanoma is an extremely aggressive malignant skin tumor with high mortality. Many types of long noncoding RNAs and microRNAs have been reported to be associated with the oncogenesis of melanoma. However, a novel lncRNA-NEAT has not been thoroughly investigated in melanoma cancer. The purposes of this study were to investigate the underlying molecular mechanism in a novel couple of lnc-NEAT1 and miR-23a-3p, as well as the function role of KLF3 in the regulation of melanoma cancer.

METHODS

28 groups of tumor tissues and normal tissues were obtained from melanoma cancer patients. We performed a series of experiments and analysis, including RT-qPCR, western blots, CCK-8 assay, and migration/invasion assay, to investigate the expressions of NEAT1, miR-23a-5p and KLF3, cell viabilities, and tumor growth in vivo.

RESULTS

In this study, we observed that the expression of NEAT1 was significantly upregulated in melanoma tissues, which remarkedly promoted the cells' proliferation, cell migration, and invasion in melanoma cell lines. Besides, NEAT1 could directly bind to miR-23a-3p, which was found to reverse the effect caused by NEAT1. MiR-23a-3p was discovered to bind to 3'UTR of KLF3, which reduced KLF3 expression. In addition, the overexpression of KLF3 could lower the effects of miR-23a-3p caused on melanoma cancer cell development.

CONCLUSION

Our results demonstrated that NEAT1 could sponge miR-23a-3p and functions via the expression of KLF3. This axis of NEAT1/miR-23a-5p/KLF3 could together regulate melanoma cancer proliferation. This might provide a new therapeutic strategy for melanoma skin cancer.Trial registration HBTCM38574839, registered 12 October 2012.

MiR-326/Sp1/KLF3: A novel regulatory axis in lung cancer progression

OBJECTIVES

To investigate the function and regulatory mechanism of Krüppel-like factor 3 (KLF3) in lung cancer.

MATERIALS AND METHODS

KLF3 expression was analysed by qRT-PCR and Western blot assays. The proliferation, migration, invasion, cycle and apoptosis were measured by CCK-8 and EdU, wound-healing and Transwell, and flow cytometry assays. The tumour growth was detected by nude mouse tumorigenesis assay. In addition, the interaction between KLF3 and Sp1 was accessed by luciferase reporter, EMSA and ChIP assay. JAK2, STAT3, PI3K and p-AKT levels were evaluated by Western blot and IHC assays.

RESULTS

The results indicated that KLF3 expression was elevated in lung cancer tissues. Knockdown of KLF3 inhibited lung cancer cell proliferation, migration and invasion, and induced cell cycle arrest and apoptosis. In addition, the downregulation of KLF3 suppressed tumour growth in vivo. KLF3 was transcriptionally activated by Sp1. miR-326 could bind to 3'UTR of Sp1 but not KLF3 and decreased the accumulation of Sp1, which further indirectly reduced KLF3 expression and inactivated JAK2/STAT3 and PI3K/AKT signaling pathways in vitro and in vivo.

CONCLUSIONS

Our data demonstrate that miR-326/Sp1/KLF3 regulatory axis is involved in the development of lung cancer, which hints the potential target for the further therapeutic strategy against lung cancer.

RNA sequencing analysis reveals protective role of kruppel-like factor 3 in colorectal cancer

The Kruppel-like factor (KLF) family of transcription factors plays an important role in embryonic formation and cancer progression. This study was performed to determine the clinical importance of the KLF family in colorectal cancer (CRC). In total, 361 patients with CRC from The Cancer Genome Atlas (TCGA) cohort were used to comprehensively study the role of the KLF family in CRC. The results were then further validated using an in-house cohort (n=194). Univariate and multivariate Cox proportional hazards models were used to assess the risk factors for survival. In the TCGA cohort, KLF3 (hazard ratio [HR], 0.501; 95% confidence interval [CI], 0.272-0.920; P=0.025), KLF14 (HR, 1.454; 95% CI, 1.059-1.995; P=0.020), and KLF17 (HR, 1.241; 95% CI, 1.030-1.494, P=0.023) were identified as potential biomarkers in the univariate analysis, but after Cox proportional hazards analysis, only KLF3 (HR, 0.473; 95% CI, 0.230-0.831; P=0.012) was shown to be independently predictive of overall survival in patients with CRC. This finding was validated in our in-house cohort, which demonstrated that KLF3 expression was an independent predictor of both overall survival (HR, 0.628; 95% CI, 0.342-0.922; P=0.035) and disease-free survival (HR, 0.421; 95% CI, 0.317-0.697, P=0.016). KLF3 expression was inversely correlated with the N stage (P=0.015) and lymphovascular invasion (P=0.020). Collectively, loss of KLF3 was correlated with aggressive phenotypes and poor survival outcomes. KLF3 might be a potential new predictor and therapeutic target for CRC. Further study is needed for a more detailed understanding of the role of KLF3 in CRC.

Blood from 'junk': the LTR chimeric transcript Pu.2 promotes erythropoiesis

Transposable elements (TEs) are a prominent feature of most eukaryotic genomes. Despite rapidly accumulating evidence for the role of TE-driven insertional mutagenesis and structural variation in genome evolution, few clear examples of individual TEs impacting biology via perturbed gene regulation are available. A recent report describes the discovery of an alternative promoter for the murine erythroid transcription factor Pu.1. This promoter is located in an ORR1A0 long terminal repeat (LTR) retrotransposon intronic to Pu.1 and is regulated by the Krüppel-like factors KLF1 and KLF3. Expression of the resultant chimeric transcript, called Pu.2, spontaneously induces erythroid differentiation in vitro. These experiments illustrate how transcription factor binding sites spread by retrotransposition have the potential to impact networks encoding key biological processes in the host genome.