STIL facilitates the development and malignant progression of triple-negative breast cancer through activation of Fanconi anemia pathway via interacting with KLF16.

BACKGROUND: STIL is an important cell cycle-regulating protein specifically recruited to the mitotic centrosome to promote the replication of centrioles in dividing cells. However, the potential role of STIL in the regulation of the biological functions of triple-negative breast cancer remains still unclear. METHODS: We screened for differentially expressed STIL in the Cancer Genome Atlas database. The expression of STIL protein in 10 pairs of breast cancer tissues and adjacent normal tissues was further assessed by western blotting. Functionally, the knockdown and overexpression of STIL have been used to explore the effects of STIL on breast cancer cell proliferation, migration, and invasion. Mechanistically, RNA-seq, dual-luciferase reporter assay, chromatin immunoprecipitation assay, mass spectrometry, immunoprecipitation assay, and DNA pull-down assay were performed. RESULTS: Breast cancer tissues and cells have higher STIL expression than normal tissues and cells. STIL knockdown impairs breast cancer cell growth, migration, and invasion, whereas STIL overexpression accelerates these processes. STIL promotes breast cancer progression by regulating FANCD2 expression, and exploration of its molecular mechanism demonstrated that STIL interacts with KLF16 to regulate the expression of FANCD2. CONCLUSIONS: Collectively, our findings identified STIL as a critical promoter of breast cancer progression that interacts with KLF16 to regulate Fanconi anemia pathway protein FANCD2. In summary, STIL is a potential novel biomarker and therapeutic target for breast cancer.

ZFP36L1 controls KLF16 mRNA stability in vascular smooth muscle cells during restenosis after vascular injury.

The RNA-binding zinc finger protein 36 (ZFP36) family participates in numerous physiological processes including transition and differentiation through post-transcriptional regulation. ZFP36L1 is a member of the ZFP36 family. This study aimed to evaluate the role of ZFP36L1 in restenosis. We found that the expression of ZFP36L1 was inhibited in VSMC-phenotypic transformation induced by TGF-ß, PDGF-BB, and FBS and also in the rat carotid injury model. In addition, we found that the overexpression of ZFP36L1 inhibited the proliferation and migration of VSMCs and promoted the expression of VSMC contractile genes; whereas ZFP36L1 interference promoted the proliferation and migration of VSMCs and suppressed the expression of contractile genes. Furthermore, the RNA binding protein immunoprecipitation and double luciferase reporter gene experiments shows that ZFP36L1 regulates the phenotypic transformation of VSMCs through the posttranscriptional regulation of KLF16. Finally, our research results in the rat carotid balloon injury animal model further confirmed that ZFP36L1 regulates the phenotypic transformation of VSMCs through the posttranscriptional regulation of KLF16 and further plays a role in vascular injury and restenosis in vivo.

KLF16 promotes pancreatic adenocarcinoma cell proliferation and migration by positively regulating SMAD6.

BACKGROUND: Pancreatic adenocarcinoma (PAAD) is a cancerous tumor with an extremely poor 5-year survival rate. The exploration of biomarkers for the diagnosis and treatment of PAAD is crucial in clinical practice. Krüppel-like factors (KLFs) are involved in a variety of biological functions in cells. According to multiple studies, KLF16 behave as an oncogene in prostate, breast and gastric cancers. However, no research has been done on the significance of KLF16 in PAAD. AIM: To explore the molecular mechanisms of KLF16 in PAAD. METHODS: KLF16 was identified in the tumor specimens and normal tissues by GEPIA database and verified by quantitative real-time PCR (qRT-PCR). Knockdown or exogenous expression of KLF16, combined with in vitro and in vivo assays, was performed to show the functional significance of KLF16. The molecular mechanism of KLF16 was demonstrated by qRT-PCR, western blotting, immunoprecipitation assay and flow cytometry. RESULTS: We showed that KLF16 was highly expressed in PAAD patients based on the GEPIA database. KLF16 silencing suppressed while KLF16 overexpression promoted the malignant function of PAAD cells. Based on RNA sequencing, we discovered that KLF16 potentiated the expression of SMAD6 in PAAD cells. SMAD6 transcript abundance was increased and positively correlated with KLF16 expression in PAAD samples. In addition, inhibiting SMAD6 was able to mitigate the effects of KLF16 overexpression on PAAD cell processes, suggesting the importance of SMAD6 in the development of KLF16-triggered PAAD. CONCLUSION: KLF16/SMAD6 axis might be explored as a therapeutic target for PAAD therapy.

KLF16 inhibits PEDV replication by activating the type I IFN signaling pathway.

KLF16, a member of KLFs (Krüppel-like factors), contributes to the progression of a variety of cancer types. There is, however, still uncertain regarding the role of KLF16 in viral replication and the signaling mechanism of type I IFN. It was discovered that KLF16 inhibited the replication of porcine epidemic diarrhea virus (PEDV) through the type I IFN signaling pathway. Besides, it can also be found that the expression of KLF16 was down-regulated after PEDV infection of LLC-PK1 cells. Furthermore, overexpression of KLF16 inhibited the replication of PEDV in Vero cells as well as LLC-PK1 cells, whereas the replication of PEDV was promoted by the knockdown of KLF16. KLF16 up-regulated the expression of interferons (IFNs) via the TRAF6-pTBK1-pIRF3 pathway with the aim of promoting the host antiviral innate immune response. In addition, the obtained findings proved that KLF16 plays a novel role in antiviral action, thereby offering novel possibilities for preventing and controlling PEDV.

Berberine attenuates diabetic atherosclerosis via enhancing the interplay between KLF16 and PPARα in ApoE-/- mice.

Cardiovascular disease caused by atherosclerosis is a leading cause of morbidity and mortality worldwide. Diabetes is a major independent risk factor for the development of atherosclerotic cardiovascular diseases. Diabetic atherosclerosis is characterized by hyperglycemia, hyperinsulinemia, and dyslipidemia. These multiple pathological factors can induce oxidative stress, inflammation, and vascular dysfunction, which can initiate and accelerate atherogenesis. Therefore, the strategy to control the development of diabetic atherosclerosis is beneficial to the patients. Berberine is one of the most promising natural products that feature significant beneficial properties on lipid and glucose metabolism, indicating the potential to improve diabetic atherosclerosis. However, the effect and underlying mechanism against diabetic atherosclerosis remain unclear. In this study, HFD and STZ were used to induce diabetic atherosclerosis in apoE-/- mice, which was followed by berberine administration. Subsequently, the degree of atherosclerotic plaque, plaque stability, and lipid and glucose metabolism were determined. In addition, the underlying mechanism was revealed by in vitro and in vivo experiments. We observed that berberine improved the dysfunction of lipid and glucose metabolism, and inhibited vascular inflammation, which reduced atherogenesis and plaque vulnerability. Mechanistically, berberine stimulated KLF16 and PPARα expression in vivo and in vitro, and activation of PPARα by berberine was through enhancing KLF16 expression and nuclear translocation. Collectively, berberine can attenuate diabetic atherosclerosis via enhancing the interplay between KLF16 and PPARα, suggesting that KLF16 is a new target of berberine and enhancing KLF16 by berberine is an efficient strategy for alleviating diabetic atherosclerosis.

Krüppel-like transcription factor 16 transcriptional up-regulation of cellular retinoic acid-binding proteins-2 promotes the invasion and migration and inhibits apoptosis of retinoblastoma cells by regulating integrin-ß1/focal adhesion kinase /extracellular signal-regulated kinase pathway.

As a common intraocular malignancy in pediatrics, retinoblastoma (RB) has high prevalence worldwide. We conducted this study, aiming to explore the molecular mechanism of Krüppel-like transcription factor 16 (KLF16)/cellular retinoic acid-binding proteins-2 (CRABP2) in regulating the invasion and migration and apoptosis of RB cells via integrin-ß1/focal adhesion kinase (FAK)/extracellular signal-regulated kinase (ERK) pathway. With the adoption of real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot, the mRNA and protein expression of CRABP2 and KLF16 were measured. In addition, the proliferation, clone formation ability and migration were detected with methyl thiazolyl tetrazolium (MTT), clone formation and wound healing assays, respectively. Furthermore, the invasion and apoptosis of transfected WERI-RB1 cells were evaluated with transwell and Tunel assays. With the application of Western blot, the expressions of proliferation-, apoptosis- and pathway-related proteins were assayed. The combination of KLF16 and CRABP2 was confirmed by dual-luciferase reporter assay and chromatin immunoprecipitation (ChIP). In this study, we found that CRABP2 gained a huge growth in RB cells and its silence promoted apoptosis but suppressed the proliferation, migration and invasiveness of WERI-RB1 cells. In addition, KLF16 could bind to CRABP2. It was also found that KLF16 overexpression reversed the effects of CRABP2 silence on the proliferation, migration and apoptosis of WERI-RB1 cells. What is more, CRABP2 silence blocked integrin-ß1/FAK/ERK signaling pathway. In conclusion, KLF16 transcriptional up-regulation of CRABP2 promoted proliferation, invasion and migration but inhibited apoptosis of RB cells by activating integrin-ß1/FAK/ERK pathway.

KLF16 enhances stress tolerance of colorectal carcinomas by modulating nucleolar homeostasis and translational reprogramming.

Translational reprogramming is part of the unfolded protein response (UPR) during endoplasmic reticulum (ER) stress, which acts to the advantage of cancer growth and development in different stress conditions, but the mechanism of ER stress-related translational reprogramming in colorectal carcinoma (CRC) progression remains unclear. Here, we identified that Krüppel-like factor 16 (KLF16) can promote CRC progression and stress tolerance through translational reprogramming. The expression of KLF16 was upregulated in CRC tissues and associated with poor prognosis for CRC patients. We found that ER stress inducers can recruit KLF16 to the nucleolus and increase its interaction with two essential proteins for nucleolar homeostasis: nucleophosmin1 (NPM1) and fibrillarin (FBL). Moreover, knockdown of KLF16 can dysregulate nucleolar homeostasis in CRC cells. Translation-reporter system and polysome profiling assays further showed that KLF16 can effectively promote cap-independent translation of ATF4, which can enhance ER-phagy and the proliferation of CRC cells. Overall, our study unveils a previously unrecognized role for KLF16 as an ER stress regulator through mediating translational reprogramming to enhance the stress tolerance of CRC cells and provides a potential therapeutic vulnerability.

Kruppel like factor 16 promotes lung adenocarcinoma progression by upregulating lamin B2.

Lung cancer is one of the most common causes of cancer-related death. In the past decade, the treatment and diagnosis of lung cancer have progressed significantly in early efforts to promote the survival of lung cancer patients. Kruppel like factor 16 (KLF16) is a zinc finger transcription factor that regulates a diverse array of developmental events and cellular processes. KLF16 is involved in the progression of various cancer types. However, the role of KLF16 in the development of lung cancer remains unknown. In this study, KLF16 was overexpressed in lung cancer samples. KLF16 downregulation inhibited lung cancer cell proliferation and migration. Conversely, KLF16 overexpression promoted lung cancer cell growth and invasion. Mechanistically, the expression level LMNB2 was suppressed by KLF16 knockdown and was promoted by KLF16 overexpression. The overall survival of patients with high LMNB2 levels was poor. Luciferase assays showed that KLF16 promoted the transcription activity of LMNB2 gene. Concomitantly, the expression level of LMNB2 was also higher in lung adenocarcinoma (LUAD) than in normal tissues, and its knockdown or overexpression can reverse the effect of KLF16 overexpression or knockdown on lung cancer cell proliferation, migration, and even tumorigenesis, indicating that LMNB2 also functions as an oncogene. In conclusion, KLF16 can be used as a potential therapeutic and preventive biomarker in lung cancer treatment and prognosis by actively regulating the expression of LMNB2.

KLF16 Downregulates the Expression of Tumor Suppressor Gene TGFBR3 to Promote Bladder Cancer Proliferation and Migration.

INTRODUCTION: Krüppel-like factors (KLFs), which comprise 17 family members, exert important functions during the development of cancer. The role of KLF16 seems controversial in carcinogenesis because both tumor suppressive and promoting effects have been reported. METHODS: The expression level of KLF16 was analyzed based on public data sets from The Cancer Genome Atlas (TCGA) and evaluated by immunohistochemical (IHC) staining. CCK8 assay, colony formation analysis, transwell assays and the PI/Annexin V-APC assay kit were performed to detect cell growth, colony formation, cell migration and apoptosis of BC cells. Xenograft tumorigenesis assay was performed to detect the KLF16 expression on BC growth in vivo. Dual-luciferase reporter assay and chromatin immunoprecipitation (ChIP)-qPCR assay were performed to analyze the interaction between KLF16 and its target. RESULTS: In this study, we explored the role of KLF16 in bladder cancer (BC). We demonstrated that KLF16 was overexpressed in human BC tissues. The high expression of KLF16 was a potential predictor of a poor prognosis in patients with BC. Interference with KLF16 expression in 563 cells, having relatively higher levels of KLF16, repressed cell proliferation and migration. In contrast, upregulation of KLF16 in T24 cells enhanced cellular function, including cell growth and migration. KLF16 also suppressed the apoptosis of BC cells. Additionally, KLF16 inhibited the expression of the TGF-type III receptor (TGFBR3) by binding to its promoter sequence and reducing transcriptional activity. There was a negative correlation between KLF16 and TGFBR3 in human BC tissues. Furthermore, TGFBR3 was revealed to be a negative regulator of BC cell proliferation and migration. KLF16 also supported BC tumorigenesis by downregulating TGFBR3 expression in vivo. DISCUSSION: These results suggested that KLF16 acts as an oncogene in BC through transcriptional inactivation of TGFBR3. This study provides evidence that targeting the KLF16/TGFBR3 axis may be beneficial for BC patients.

Silencing KLF16 inhibits oral squamous cell carcinoma cell proliferation by arresting the cell cycle and inducing apoptosis.

Krüppel-like factor 16 (KLF16), a member of the Krüppel-like factor (KLF) family, has been extensively investigated in multiple cancer types. However, the role of KLF16 in oral squamous cell carcinoma (OSCC) remains unknown. Thus, we conducted this study to investigate its related mechanism. KLF16 expression in OSCC cell lines was quantified by western blotting. Then, OECM1 and OC3 cells were divided into Blank, siCtrl, siKLF16#1 and siKLF16#2 groups. Subsequently, cell proliferation was detected using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assays, cell migration and invasion were detected with wound healing and Transwell assays, and cell cycle distribution and cell apoptosis were detected via flow cytometry. KLF16, p21, CDK4, Cyclin D1 and p-Rb expression was detected by western blotting. Finally, xenograft models were established in nude mice to observe the in vivo effects of KLF16 on OSCC. KLF16 protein expression was upregulated in OSCC cells. Compared to the cells in the Blank group, the OECM1 and OC3 cells in the siKLF16#1 group and siKLF16#2 group exhibited a sharp decrease in proliferation but a remarkable increase in apoptosis. Moreover, the proportion of cells in the G0/G1 phase notably increased and that in the S phase decreased, with evident decreases in cell invasion and migration. Moreover, KLF16, cyclin-dependent kinase 4 (CDK4), Cyclin D1 and p-Rb protein expression was upregulated, but p21 expression was downregulated. The mice in the siKLF16#1 and siKLF16#2 xenograft model groups exhibited slower tumour growth and smaller tumours with evident downregulation of Ki67 expression compared to the mice in the Blank group. KLF16 expression was upregulated in OSCC cells, and interfering with KLF16 led to cell cycle arrest, inhibited OSCC cell growth and promoted cell apoptosis.

Knock out hepatic Krüppel-like factor 16 (KLF16) improve myocardial damage and promoted myocardial protection of myocardial ischemia-reperfusion via anti-oxidative and anti-inflammation effects by TFAM/PPARß signal passage.

This study is aimed at investigating mechanisms and effects of Krüppel-like factor 16 (KLF16) affects myocardial ischemia-reperfusion. Patients with myocardial ischemia-reperfusion and normal volunteer were collected. C57BL6J male mice were located left anterior descending coronary artery (LAD). H9c2 cell was induced with hydrogen peroxide (H2O2) and Lipopolysaccharide (LPS). Serum KLF16 mRNA expression was increased in myocardial ischemia-reperfusion. Serum mRNA of KLF16 was positive correlation with serum creatine kinase MB (CK-MB) or creatine kinase (CK) levels in patients with myocardial ischemia-reperfusion. The expression of KLF16 mRNA and protein in mice with myocardial ischemia-reperfusion were also increased. The inhibition of KLF16 reduced oxidative stress and inflammation, and presented myocardial ischemia (MI) in vivo model of myocardial ischemia-reperfusion. Mitochondrial transcription factor A (TFAM)/peroxisome proliferator-activated receptor-beta (PPARß) signal passage is target spot of KLF16 in Myocardial ischemia-reperfusion. TFAM interlink KLF16 in myocardial ischemia-reperfusion. TFAM participate in KLF16 affects myocardial ischemia-reperfusion. PPARß promoter region KLF16 affects myocardial ischemia-reperfusion. These results firstly demonstrated that knock-out KLF16 reduced oxidative stress and inflammation, and presented MI in vivo model of myocardial ischemia-reperfusion through the induction of PPARß by TFAM, may provide a novel therapeutic strategy for myocardial ischemia-reperfusion.

A novel mechanism driving poor-prognostic gastric cancer: overexpression of the transcription factor Krüppel-like factor 16 promotes growth and metastasis of gastric cancer through regulating the Notch pathway.

Gastric cancer (GC) is one of the most common malignant tumors worldwide and has high rates of morbidity and mortality. This study investigated the role of Krüppel-like factor 16 (KLF16) in GC. Real-time polymerase chain reaction, Western blotting, and immunohistochemistry were used to examine the expression of KLF16 in gastric cells and tissues. Gene overexpression and silencing were applied to study the involvement of KLF16 in GC cell growth and metastasis along with its underlying mechanism. The results indicate that KLF16 overexpression is significantly associated with nodal status, distant metastasis, staging, degree of differentiation, vascular invasion, and patient survival. Multivariate Cox proportional hazards regression model analysis revealed that the overexpression of KLF16 is an independent prognostic biomarker of GC. The in vitro study revealed that up-regulated KLF16 accelerates cell growth and metastasis, whereas the inhibition of KLF16 suppresses these cellular activities. The results of an animal study also indicated that the overexpression and silencing of KLF16 accelerate and repress xenograft proliferation and metastasis. Further studies of affected cell growth and metastasis revealed that KLF16 modulates the cell cycle and epithelial-mesenchymal transition through transcriptional regulation of microfibrillar-associated protein 5. Collectively, these results reveal that KLF16 overexpression is a potential prognostic biomarker and therapeutic target for the treatment of GC.

circSLC8A1 sponges miR-671 to regulate breast cancer tumorigenesis via PTEN/PI3k/Akt pathway.

Breast cancer is the most frequently diagnosed and the leading cause of cancer-related deaths in women worldwide. However, the role of circSLC8A1 in breast cancer remains elusive. Herein, a cohort of 77 breast tumors and paired adjacent normal mammary tissues were collected. We demonstrated that circSLC8A1 was significantly down-regulated in breast cancer tissues and cell lines, of which expression was negatively correlated with clinical severity and dismal prognosis. Overexpression of circSLC8A1 suppressed cell proliferation, migration and invasion in vitro, and inhibited tumor growth in vivo. CircSLC8A1 directly targeted miR-671 to execute tumor suppressive activities via regulating PI3k/Akt signaling. Krüppel-like factor 16 (KLF16), a transcriptional activator of PTEN, was identified as a target of miR-671. Furthermore, circSLC8A1 could sponge miR-671 to suppress breast tumor growth via PTEN/PI3k/Akt signaling in vivo. In summary, circSLC8A1/miR-671 regulates breast cancer progression through PTEN/PI3k/Akt signaling, which may provide efficient therapeutic target for this devastating cancer.

KLF16 overexpression deleteriously affects the proliferation and migration of retinoblastoma by transcriptionally repressing BCL2L15.

Krüppel-like factors (KLFs) are transcription factors that control the expression of downstream genes. The role of KLFs has been reported in cancers. KLF16 promotes the proliferation of gastric cancer cells by upregulating p21, while suppresses the tumorigenesis of glioma through targeting TFAM. The function of KLF16 is controversial in cancer development. In this study, we aimed to investigate the role of KLF16 in retinoblastoma (RB). KLF16 was highly expressed in RB tissues and cells. Overexpression of KLF16 promoted the proliferation, growth and migration of RB cells. By contrast, KLF16 interference showed opposite effects. Cell cycle arrest and apoptosis were induced or repressed by KLF16 knockdown or overexpression, respectively. Mechanistically, BCL2 like 15 (BCL2L15), an apoptosis gene, was negatively regulated by KLF16. Luciferase reporter and ChIP assay showed that KLF16 transcriptionally repressed the expression of BCL2L15 by binding to its promoter. BCL2L15 was lowly expressed in RB tissues. Additionally, overexpression of BCL2L15 inhibited the proliferation and increased the apoptosis in RB cells. Our study identifies that KLF16 contributes to RB cell proliferation and migration by negatively regulating BCL2L15.

KLF16 Affects the MYC Signature and Tumor Growth in Prostate Cancer.

BACKGROUND: KLF16, a member of the Kruppel-like factor (KLF) family, functions in the regulation of dopaminergic transmission, metabolism, and endocrinology. However, the role of KLF16 in prostate cancer (PCa) remains unknown. METHODS: We screened the expression of KLFs in PCa based on bioinformatics analysis. The protein levels of KLF16 in PCa specimens were confirmed by immunohistochemistry. Inhibiting KLF16 by RNA interference with shRNA was used to determine the effects of KLF16 on PCa cell growth in vitro and in vivo. RNA sequencing was used to investigate the signaling regulated by KLF16 in PCa. Bioinformatics analysis was also used to determine the possible correlations of KLF16 and signaling in PCa cohorts. RESULTS: Bioinformatics analysis showed that KLF16 may be required for PCa development. Notably, the expression of KLF16 was elevated in human PCa tissues. In vitro and in vivo experiments both demonstrated that depleting KLF16 significantly inhibited the growth of PCa cells. Downregulation of KLF16 significantly decreased the expression of MYC signaling in PCa cells. Furthermore, KLF16 expression was correlated with MYC signaling activity. CONCLUSION: KLF16 was overexpressed in PCa tissues compared to normal tissues. KLF16 knockdown suppressed PCa cell growth in vitro and in vivo, and a deficiency of KLF16 inhibited activation of MYC signaling.

Dopamine D1 Receptor (D1R) Expression Is Controlled by a Transcriptional Repressor Complex Containing DISC1.

Disrupted-in-Schizophrenia 1 (DISC1) is a scaffold protein implicated in various psychiatric diseases. Dysregulation of the dopamine system has been associated with DISC1 deficiency, while the molecular mechanism is unclear. In this study, we propose a novel molecular mechanism underlying the transcriptional regulation of the dopamine D1 receptor (D1R) in the striatum via DISC1. We verified the increase in D1R at the transcriptional level in the striatum of DISC1-deficient mouse models and altered histone acetylation status at the D1r locus. We identified a functional interaction between DISC1 and Krüppel-like factor 16 (KLF16). KLF16 translocates DISC1 into the nucleus and forms a regulatory complex by recruiting SIN3A corepressor complexes to the D1r locus. Moreover, DISC1-deficient mice have altered D1R-mediated signaling in the striatum and exhibit hyperlocomotion in response to cocaine; the blockade of D1R suppresses these effects. Taken together, our results suggest that nuclear DISC1 plays a critical role in the transcriptional regulation of D1R in the striatal neuron, providing a mechanistic link between DISC1 and dopamine-related psychiatric symptoms.

Long noncoding RNA-RNCR3 overexpression deleteriously affects the growth of glioblastoma cells through miR-185-5p/Krüppel-like factor 16 axis.

Glioblastoma (GBM) is a devastating and highly aggressive tumor, which is apoptosis resistant and difficult to cure. Recently, long noncoding RNAs have been shown to play a pivotal role in GBM progression. Evidence has suggested that retinal noncoding RNA3 (RNCR3) is a GBM-associated noncoding RNA and is under-expressed in GBM. However, the function and mechanism of RNCR3 on GBM cell growth and apoptosis are still uncertain. In the current study, we found that the level of RNCR3 is decreased in U87, U251, U373, and A172 GBM cell lines when compared with the normal human astrocytes. Elevating long noncoding RNA RNCR3 expression markedly inhibits U87 and U251 cell survival and proliferation. Further studies indicated that RNCR3 overexpression promotes U87 and U251 cell apoptosis and activity caspase-3/7. Moreover, we found that RNCR3 overexpression promotes Krüppel-like factor 16 (KLF16) expression through inhibiting the level of miR-185-5p. We demonstrated that KLF16 is a direct target of miR-185-5p. An increased miR-185-5p level by a miR-185-5p mimic or decreased KLF16 by KLF16 small interfering RNA both reversed the function of RNCR3 overexpression on GBM cell growth and apoptosis. In summary, this study focuses on investigating the key molecular mechanisms of RNCR3 involved in GBM cell growth and apoptosis. Our data indicated that RNCR3 overexpression inhibits cell growth and induces its apoptosis through the miR-185-5p/KLF16 axis.

KLF16 suppresses human glioma cell proliferation and tumourigenicity by targeting TFAM.

BACKGROUND: This study aims to via unveiling the novel mechanisms of KLF16 in regulating expression of genes involved in glioma. METHODS: KLF16 or KLF16-siRNA was transfected to U87MG cells by lentivirus. Colony formation assay was applied for detecting cell proliferation. MTT assay was adopted to assess cell viability. TUNEL assay was selected to evaluate cell apoptosis. Flow cytometry was used to determine cell cycle. Real-time PCR was performed to test mRNA expression. Western blot was used to detect protein level. Luciferase assay was applied to confirm the regulatory relationship between KLF16 and Mitochondrial transcription factor A (TFAM). Chromatin immunoprecipitation was adopted to test the protein binding site. The nude mouse transplantation tumour experiment was selected to test cancer cell proliferation in vivo. RESULTS: KLF16 was decreased in glioma cells and tissues. KLF16 obviously restrained U87MG cell proliferation both in vivo and in vitro. KLF16 transfection reduced mRNA and protein levels related to cell proliferation. KLF16 targeted a putative binding site near the transcription start sites (TSSs) of TFAM gene, thus suppressing glioma cell proliferation. KLF16-siRNA exhibited the opposite impact. KLF16 presented significant negative correlation with TFAM level in glioma patients. CONCLUSIONS: KLF16 is a key regulator of glioma cell proliferation by directly targeting TFAM.

KLF16 promotes proliferation in gastric cancer cells via regulating p21 and CDK4.

Krüppel-like factors (KLFs), such as KLF4, KLF2, KLF5 and KLF15, have been extensively investigated in multi-cancers. However, KLF16, a member of KLFs, hasn't been well identified in cancer, especially in gastric cancer (GC). Here, we investigated the roles of KLF16 in GC. In present study, we found that KLF16 expression levels were significantly up-regulated in GC tissues compared to adjacent normal tissues both in protein and mRNA levels by using immunohistochemistry assays (IHC) and real-time quantitative PCR (qPCR). And KLF16 expression levels were positively correlated to tumor size, invasion depth, lymphatic metastasis and TNM stage. Furthermore, KLF16 expression also could predict prognosis in patients with GC. Moreover, the knock-down of KLF16 could significantly suppress proliferation via increasing p21 expression and decreasing CDK4 expression in GC cell lines. In summary, these findings demonstrate that KLF16 plays a significant role in GC progression and could be a new therapeutic target for GC patients.