LZTFL1 suppresses gastric cancer cell migration and invasion through regulating nuclear translocation of β-catenin

The association of rs17713054 with Neanderthal origin at 3p21.31 locus with the severity of COVID-19 in Iranian patients

Since the COVID-19 pandemic, the diversity of clinical manifestations in patients has been a tremendous challenge. It seems that genetic variations, as one of the players, contribute to the variety of symptoms. Genome-wide association studies have demonstrated the influence of certain genomic regions on the disease prognosis. Particularly, a haplotype at 3p21.31 locus, inherited from Neanderthals, showed an association with COVID-19 severity. Despite several studies regarding this haplotype, some key variants are not sufficiently addressed. In the present study, we investigated the association of rs17713054 at 3p21.31 with COVID-19 severity. We analyzed the genotype of 251 Iranian COVID-19 patients (151 patients with asymptomatic to mild form as control and 100 patients with severe to critical symptoms without any comorbidities as case group) using the ARMS-PCR method. Results demonstrated that the A allele confers an almost twofold increased risk for COVID-19 severity (P value = 0.008). The AA genotype also raises the risk by more than 11 times following the recessive model (P value = 0.013). In conclusion, the A allele in rs17713054 was a risk allele in Iranian patients and was independently associated with COVID-19 severity. More studies are beneficial to confirm these findings in other populations and to develop strategies for risk assessment, prevention, and personalized medicine.

Anti-inflammation of LZTFL1 knockdown in OVA-induced asthmatic mice: Through ERK/GATA3 signaling pathway

Asthma is a common chronic respiratory disease characterized by Th2-type inflammation in the airways. Leucine zip transcription factor-like 1 (LZTFL1) has been implicated in the regulation of Th2-related factors. The knockdown of LZTFL1 resulted in decreased levels of IL-4, IL-5, and IL-13. We hypothesize that LZTFL1 may have an effect on asthma. We established an acute asthmatic mouse model using the Ovalbumin (OVA) sensitization, and we found that LZTFL1 expression was upregulated in OVA-induced CD4 + T cells. Mice challenged with OVA were administered 5 × 107 TU of lentivirus via tail vein injection. LZTFL1 knockdown reversed the frequency of sneezing and nose rubbing in OVA mice. LZTFL1 knockdown reduced inflammatory cell infiltration, reduced goblet cell numbers, and mitigated collagen deposition in lung tissue. LZTFL1 knockdown decreased the levels of OVA-specific IgE, IL-4, IL-5, and IL-13 in alveolar lavage fluid of asthmatic mice. Furthermore, LZTFL1 knockdown inhibited the aberrant activation of MEK/ERK signaling pathway in asthmatic mice. GATA binding protein 3 (GATA3) is an essential transcription factor in Th2 differentiation. Flow cytometry results revealed that LZTFL1 knockdown reduced the number of GATA3 + CD4 + Th2 cells, while it did not affect the stability of GATA3 mRNA. This may be attributed to ERK signaling which stabilized GATA3 by preventing its ubiquitination and subsequent degradation. In conclusion, LZTFL1 knockdown attenuates inflammation and pathological changes in OVA-induced asthmatic mice through ERK/GATA3 signaling pathway.

Genetic variants associated with SARS-CoV-2 infection also affect lung function and asthma severity

Background

Host genetic factors may be associated with COVID-19 unfavourable outcomes. The first genome-wide association study (GWAS) conducted in individuals with respiratory failure due to COVID-19 revealed susceptibility loci close to six genes (SLC6A20, LZTFL1, CCR9, FYCO1, CXCR6 and XCR1) and the ABO blood-group gene. We aimed to investigate how polymorphisms in those genes could relate to lung function and severe asthma in a Brazilian population.

Methods

DNA samples of 784 individuals following the ProAR (Programa para Controle da Asma e Rinite Alérgica da Bahia) were genotyped by the Multi-Ethnic Global Array panel with ∼2 million polymorphisms (Illumina). Polymorphisms in SLC6A20, LZTFL1, CCR9, FYCO1, CXCR6, XCR1 and the ABO blood-group gene were evaluated. Logistic regression for severe asthma, airway obstruction and lack of FEV1 reversibility was performed using PLINK software 1.9, in the additive model and was adjusted for sex, age and PCA-1. Pairwise Linkage disequilibrium analyses were performed using Haploview 4.2. The haplotypes and gene score analyses were performed in the SNPstat tool. In silico functions of polymorphisms were analysed using rSNPbase and RegulomeDB plataforms.

Results

We identified the rs8176733 (G allele) and rs8176725 (A allele) in the ABO blood-group gene as risk factors for severe asthma, lower pulmonary obstruction and lack of FEV1 reversibility. Polymorphisms in CCR9 are risk factors for both severe asthma (A allele of rs34338823) and airway obstruction (A allele of rs6806802). The markers rs13079478 (A allele) and rs75817942 (A allele) in FYCO1 are related to more severe asthma and a lack of FEV1 reversibility, respectively. We identified the A allele of both rs35731912 and rs34338823 in LZTFL1 as risk factors for severe asthma. The marker rs6806802 (C allele) was associated with airway obstruction and rs7614952 (A allele), rs7625839 (G allele) and rs112509260 (A allele) are related to a lack of FEV1 reversibility. The A allele of rs2531747 in the SLC6A20 gene is also associated with severe asthma. Conversely, polymorphisms in XCR1 play a protective role in relation to severe asthma (A allele of rs2036295) and airway obstruction (A allele of rs2036295). Additionally, we found that individuals with a higher number of risk alleles have a greater risk of severe asthma, airway obstruction and FEV1 reversibility.

Conclusion

Our study suggests that polymorphisms in genes associated with respiratory failure in SARS-CoV-2-infected individuals are associated with greater susceptibility to severe asthma and reduced lung function in subjects with asthma.

LZTFL1 inhibits kidney tumor cell growth by destabilizing AKT through ZNRF1-mediated ubiquitin proteosome pathway

LZTFL1 is a tumor suppressor located in chromosomal region 3p21.3 that is deleted frequently and early in various cancer types including the kidney cancer. However, its role in kidney tumorigenesis remains unknown. Here we hypothesized a tumor suppressive function of LZTFL1 in clear cell renal cell carcinoma (ccRCC) and its mechanism of action based on extensive bioinformatics analysis of patients' tumor data and validated it using both gain- and loss-functional studies in kidney tumor cell lines and patient-derive xenograft (PDX) model systems. Our studies indicated that LZTFL1 inhibits kidney tumor cell proliferation by destabilizing AKT through ZNRF1-mediated ubiquitin proteosome pathway and inducing cell cycle arrest at G1. Clinically, we found that LZTFL1 is frequently deleted in ccRCC. Downregulation of LZTFL1 is associated with a poor ccRCC outcome and may be used as prognostic maker. Furthermore, we show that overexpression of LZTFL1 in PDX via lentiviral delivery suppressed PDX growth, suggesting that re-expression of LZTFL1 may be a therapeutic strategy against ccRCC.

The Role of Different Types of microRNA in the Pathogenesis of Breast and Prostate Cancer

Micro ribonucleic acids (microRNAs or miRNAs) form a distinct subtype of non-coding RNA and are widely recognized as one of the most significant gene expression regulators in mammalian cells. Mechanistically, the regulation occurs through microRNA binding with its response elements in the 3'-untranslated region of target messenger RNAs (mRNAs), resulting in the post-transcriptional silencing of genes, expressing target mRNAs. Compared to small interfering RNAs, microRNAs have more complex regulatory patterns, making them suitable for fine-tuning gene expressions in different tissues. Dysregulation of microRNAs is well known as one of the causative factors in malignant cell growth. Today, there are numerous data points regarding microRNAs in different cancer transcriptomes, the specificity of microRNA expression changes in various tissues, and the predictive value of specific microRNAs as cancer biomarkers. Breast cancer (BCa) is the most common cancer in women worldwide and seriously impairs patients' physical health. Its incidence has been predicted to rise further. Mounting evidence indicates that microRNAs play key roles in tumorigenesis and development. Prostate cancer (PCa) is one of the most commonly diagnosed cancers in men. Different microRNAs play an important role in PCa. Early diagnosis of BCa and PCa using microRNAs is very useful for improving individual outcomes in the framework of predictive, preventive, and personalized (3P) medicine, thereby reducing the economic burden. This article reviews the roles of different types of microRNA in BCa and PCa progression.

Identification of LZTFL1 as a candidate effector gene at a COVID-19 risk locus

The severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) disease (COVID-19) pandemic has caused millions of deaths worldwide. Genome-wide association studies identified the 3p21.31 region as conferring a twofold increased risk of respiratory failure. Here, using a combined multiomics and machine learning approach, we identify the gain-of-function risk A allele of an SNP, rs17713054G>A, as a probable causative variant. We show with chromosome conformation capture and gene-expression analysis that the rs17713054-affected enhancer upregulates the interacting gene, leucine zipper transcription factor like 1 (LZTFL1). Selective spatial transcriptomic analysis of lung biopsies from patients with COVID-19 shows the presence of signals associated with epithelial-mesenchymal transition (EMT), a viral response pathway that is regulated by LZTFL1. We conclude that pulmonary epithelial cells undergoing EMT, rather than immune cells, are likely responsible for the 3p21.31-associated risk. Since the 3p21.31 effect is conferred by a gain-of-function, LZTFL1 may represent a therapeutic target.

Leucine zipper transcription factor-like 1 (LZTFL1), an intraflagellar transporter protein 27 (IFT27) associated protein, is required for normal sperm function and male fertility

Intraflagellar transport (IFT) is an evolutionarily conserved mechanism essential for the assembly and maintenance of most eukaryotic cilia and flagella, including mammalian sperm tails. Depletion of IFT27, a component of the IFT complex, in male germ cells results in infertility associated with disrupted sperm flagella structure and motility. Leucine zipper transcription factor-like 1 (LZTFL1) is an IFT27 associated protein. LZTFL1, also known as BBS17, is a Bardet-Biedl syndrome (BBS) associated protein. Patients carrying biallelic variants of LZTFL1 gene exhibit the common BBS phenotypes. The global Lztfl1 knockout mice showed abnormal growth rate and retinal degeneration, typical of BBS phenotype. However, it is not clear if Lztfl1 has a role in male fertility. The LZTFL1 protein is highly and predominantly expressed in mouse testis. During the first wave of spermatogenesis, the protein is only expressed during spermiogenesis phase from the round spermatid stage and displays a cytoplasmic localization with a vesicular distribution pattern. At the elongated spermatid stage, LZTFL1 is present in the developing flagella and appears also close to the manchette. Fertility of Lztfl1 knockout mice was significantly reduced and associated with low sperm motility and a high level of abnormal sperm (astheno-teratozoospermia). In vitro assessment of fertility revealed reduced fertilization and embryonic development when using sperm from homozygous mutant mice. In addition, we observed a significant decrease of the testicular IFT27 protein level in Lztfl1 mutant mice contrasting with a stable expression levels of other IFT proteins, including IFT20, IFT81, IFT88 and IFT140. Overall, our results support strongly the important role of LZTFL1 in mouse spermatogenesis and male fertility.

lncRNA SNHG6 promotes hepatocellular carcinoma progression by interacting with HNRNPL/PTBP1 to facilitate SETD7/LZTFL1 mRNA destabilization

The lncRNA SNHG6 (small nucleolar RNA host gene 6) plays vital roles in tumorigenesis and the progression of hepatocellular carcinoma (HCC). However, the regulatory mechanisms of SNHG6 are largely unknown. In this study, we identified, via quantitative proteomics, specific cytoskeleton-associated proteins and enzyme modulators to be potential targets of SNHG6. SNHG6 reduced the mRNA levels of lysine methyltransferase, SET domain containing 7 (SETD7) and leucine zipper transcription factor-like 1 (LZTFL1) by posttranscriptional destabilization. Silencing of SETD7 or LZTFL1 reversed the suppressive effects of SNHG6 knockdown on HCC progression. Heterogeneous nuclear ribonucleoprotein L (HNRNPL) and polypyrimidine tract binding protein 1 (PTBP1) were identified as SNHG6-interacting proteins that bind to SETD7 or LZTFL1 mRNA. Forced expression of SNHG6 led to HNRNPL being competitively adsorbed by SNHG6, thereby removing its stabilizing effect on SETD7. Concurrently, the functional SNHG6-PTBP1 complex facilitated the degradation of LZTFL1 mRNA in hepatoma cells. These results indicated that SNHG6 promotes HCC progression by functioning as a "decoy plus guide" for HNRNPL and PTBP1 to facilitate mRNA decay of SETD7 and LZTFL1, thereby serving as a novel therapeutic target for HCC.

PHF19 inhibition as a therapeutic target in multiple myeloma

Epigenetic deregulation is increasingly recognized as a contributing pathological factor in multiple myeloma (MM). In particular tri-methylation of H3 lysine 27 (H3K27me3), which is catalyzed by PHD finger protein 19 (PHF19), a subunit of the Polycomb Repressive Complex 2 (PRC2), has recently shown to be a crucial mediator of MM tumorigenicity. Overexpression of PHF19 in MM has been associated with worse clinical outcome. Yet, while there is mounting evidence that PHF19 overexpression plays a crucial role in MM carcinogenesis downstream mechanisms remain to be elucidated. In the current study we use a functional knock down (KD) of PHF19 to investigate the biological role of PHF19 and show that PHF19KD leads to decreased tumor growth in vitro and in vivo. Expression of major cancer players such as bcl2, myc and EGR1 were decreased upon PHF19KD further underscoring the role of PHF19 in MM biology. Additionally, our results highlighted the prognostic impact of PHF19 overexpression, which was significantly associated with worse survival. Overall, our study underscores the premise that targeting the PHF19-PRC2 complex would open up avenues for novel MM therapies.

Tiny miRNAs Play a Big Role in the Treatment of Breast Cancer Metastasis

Simple Summary

MicroRNAs (miRNAs) have emerged as important regulators of tumour progression and metastasis in breast cancer. Through a review of multiple studies, this paper has identified the key regulatory roles of oncogenic miRNAs in breast cancer metastasis including the potentiation of angiogenesis, epithelial-mesenchymal transition, the Warburg effect, and the tumour microenvironment. Several approaches have been studied for selective targeting of breast tumours by miRNAs, ranging from delivery systems such as extracellular vesicles and liposomes to the use of prodrugs and functionally modified vehicle-free miRNAs. While promising, these miRNA-based therapies face challenges including toxicity and immunogenicity, and greater research on their safety profiles must be performed before progressing to clinical trials.

Abstract

Distant organ metastases accounts for the majority of breast cancer deaths. Given the prevalence of breast cancer in women, it is imperative to understand the underlying mechanisms of its metastatic progression and identify potential targets for therapy. Since their discovery in 1993, microRNAs (miRNAs) have emerged as important regulators of tumour progression and metastasis in various cancers, playing either oncogenic or tumour suppressor roles. In the following review, we discuss the roles of miRNAs that potentiate four key areas of breast cancer metastasis—angiogenesis, epithelial-mesenchymal transition, the Warburg effect and the tumour microenvironment. We then evaluate the recent developments in miRNA-based therapies in breast cancer, which have shown substantial promise in controlling tumour progression and metastasis. Yet, certain challenges must be overcome before these strategies can be implemented in clinical trials.

Leucine zipper transcription factor-like 1 binds adaptor protein complex-1 and 2 and participates in trafficking of transferrin receptor 1

LZTFL1 participates in immune synapse formation, ciliogenesis, and the localization of ciliary proteins, and knockout of LZTFL1 induces abnormal distribution of heterotetrameric adaptor protein complex-1 (AP-1) in the Lztfl1-knockout mouse photoreceptor cells, suggesting that LZTFL1 is involved in intracellular transport. Here, we demonstrate that in vitro LZTFL1 directly binds to AP-1 and AP-2 and coimmunoprecipitates AP-1 and AP-2 from cell lysates. DxxFxxLxxxR motif of LZTFL1 is essential for these bindings, suggesting LZTFL1 has roles in AP-1 and AP-2-mediated protein trafficking. Since AP-1 and AP-2 are known to be involved in transferrin receptor 1 (TfR1) trafficking, the effect of LZTFL1 on TfR1 recycling was analyzed. TfR1, AP-1 and LZTFL1 from cell lysates could be coimmunoprecipitated. However, pull-down results indicate there is no direct interaction between TfR1 and LZTFL1, suggesting that LZTFL1 interaction with TfR1 is indirect through AP-1. We report the colocalization of LZTFL1 and AP-1, AP-1 and TfR1 as well as LZTFL1 and TfR1 in the perinuclear region (PNR) and the cytoplasm, suggesting a potential complex between LZTFL1, AP-1 and TfR1. The results from the disruption of adaptin recruitment with brefeldin A treatment suggested ADP-ribosylation factor-dependent localization of LZFL1 and AP-1 in the PNR. Knockdown of AP-1 reduces the level of LZTFL1 in the PNR, suggesting that AP-1 plays a role in LZTFL1 trafficking. Knockout of LZTFL1 reduces the cell surface level and the rate of internalization of TfR1, leading to a decrease of transferrin uptake, efflux, and internalization. However, knockout of LZTFL1 did not affect the cell surface levels of epidermal growth factor receptor and cation-independent mannose 6-phosphate receptor, indicating that LZTFL1 specifically regulates the cell surface level of TfR1. These data support a novel role of LZTFL1 in regulating the cell surface TfR1 level by interacting with AP-1 and AP-2.

TRIM58 suppresses the tumor growth in gastric cancer by inactivation of β-catenin signaling via ubiquitination

Objective: To investigate and define the underlying molecular mechanism of tripartite motif-containing 58 (TRIM58) in regulating the tumor growth of gastric cancer (GC).Methods: TRIM58 expression in GC tissues and cells was detected by real-time PCR and Western blot, followed by lentiviral-induced overexpression or knockdown of TRIM58. Subsequently, CCK8, BrdU-ELISA, flow cytometry, immunoprecipitation, in vitro animal experiments and immunochemistry were performed to explore the function of TRIM58. Western blotting was used to detect β-catenin, C-myc, Cyclin D1, and survivin expression.Results: TRIM58 expression was significantly reduced in tumor tissues of GC patients and GC cell lines, whereas β-catenin, C-myc, Cyclin D1, and survivin were highly expressed. Overexpression of TRIM58 in GC cells resulted in decreases in β-catenin, C-myc, Cyclin D1, and survivin protein expression and significantly suppressed proliferation by preventing cell-cycle progression and promoting cell apoptosis. Conversely, TRIM58 knockdown resulted in the opposite effects. Furthermore, the effect of TRIM58 knockdown on GC cells was potently reversed by a β-catenin inhibitor, XAV939. Immunoprecipitations showed the interaction between TRIM58 and β-catenin, and TRIM58 overexpression significantly enhanced β-catenin degradation. In addition, we found a significant decrease in the growth and weight of tumors and an increase in tumor cell apoptosis in TRIM58-overexpression nude mice, which were also accompanied by reduced β-catenin expression.Conclusions: These data suggest that TRIM58 may function as a tumor suppressor in GC and potentially suppress the tumor growth of gastric cancer by inactivation of β-catenin signaling via ubiquitination.

Lztfl1/BBS17 controls energy homeostasis by regulating the leptin signaling in the hypothalamic neurons

Leptin receptor (LepRb) signaling pathway in the hypothalamus of the forebrain controls food intake and energy expenditure in response to an altered energy state. Defects in the LepRb signaling pathway can result in leptin-resistance and obesity. Leucine zipper transcription factor like 1 (Lztfl1)/BBS17 is a member of the Bardet-Biedl syndrome (BBS) gene family. Human BBS patients have a wide range of pathologies including obesity. The cellular and molecular mechanisms underlying Lztfl1-regulated obesity are unknown. Here, we generated Lztfl1f/f mouse model in which Lztfl1 can be deleted globally and in tissue-specific manner. Global Lztfl1 deficiency resulted in pleiotropic phenotypes including obesity. Lztfl1-/- mice are hyperphagic and showed similar energy expenditure as WT littermates. The obese phenotype of Lztfl1-/- mice is caused by the loss of Lztfl1 in the brain but not in the adipocytes. Lztfl1-/- mice are leptin-resistant. Inactivation of Lztfl1 abolished phosphorylation of Stat3 in the LepRb signaling pathway in the hypothalamus upon leptin stimulation. Deletion of Lztfl1 had no effect on LepRb membrane localization. Furthermore, we observed that Lztfl1-/- mouse embryonic fibroblasts (MEFs) have significantly longer cilia than WT MEFs. We identified several proteins that potentially interact with Lztfl1. As these proteins are known to be involved in regulation of actin/cytoskeleton dynamics, we suggest that Lztfl1 may regulate leptin signaling and ciliary structure via these proteins. Our study identified Lztfl1 as a novel player in the LepRb signaling pathway in the hypothalamus that controls energy homeostasis.

LAMC1 is a prognostic factor and a potential therapeutic target in endometrial cancer

OBJECTIVE

With the emerging significance of genetic profiles in the management of endometrial cancer, the identification of tumor-driving genes with prognostic value is a pressing need. The LAMC1 gene, encoding the laminin subunit gamma 1 (LAMC1) protein, has been reported to be involved in the progression of various malignant tumors. In this study, we aimed to investigate the role of LAMC1 in endometrial cancer and elucidate the underlying mechanism.

METHODS

We evaluated the immunohistochemical expression of LAMC1 in atypical endometrial hyperplasia and endometrial cancer. Within the endometrial cancer cases, we analyzed the association of LAMC1 overexpression with clinicopathological factors and prognosis. Furthermore, to indentify genes influenced by LAMC1 overexpression, we transfected HEC50B and SPAC-S cells with siRNA targeting LAMC1 and conducted microarray gene expression assays.

RESULTS

While none of the atypical endometrial hyperplasia specimens exhibited LAMC1 overexpression, endometrial cancer possessed a significantly higher LAMC1 overexpression rate. LAMC1 overexpression was strongly associated with histological type, lymphovascular space invasion, lymph node metastasis, advanced International Federation of Gynecology and Obstetrics stage, and poor overall survival in endometrial cancer. Gene expression microarray analysis identified 8 genes correlated with tumor progression (LZTFL1, TAPT1, SEL1L, PAQR6, NME7, TMEM109, CCDC58, and ANKRD40) that were commonly influenced in HEC50B and SPAC-S by LAMC1 silencing.

CONCLUSION

LAMC1 overexpression is a potent biomarker for identifying endometrial cancer patients needing aggressive adjuvant therapy. We elucidated 8 candidate genes that may mediate progression of LAMC1 overexpressing cancer. Further investigation of the underlying mechanism should lead to the discovery of new therapeutic targets.

Tumor suppressive functions of LZTFL1 in hepatocellular carcinoma

Background: Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related mortality worldwide. The poor survival may be due to tumor recurrence and metastasis. Growing evidence indicates that Leucine Zipper Transcription Factor-like 1 (LZTFL1) plays an important role in tumor progression of several cancers such as lung cancer and gastric cancer. Methods: Real-time PCR was performed to evaluate LZTFL1 expression level in HCC cell lines and patient specimens. The relationship between LZTFL1 expression and the clinicopathological data of the patients was analyzed. Stable cell lines with overexpressing LZTFL1 were set-up, and the cell proliferation, migration, and invasion abilities were analyzed. The protein expression was measured by Western blotting. Results: Here, we found LZTFL1 expression was decreased in human HCC specimens and HCC cell lines. Downregulation of LZTFL1 expression was correlated with tumor stage and metastasis. The ectopic overexpression of LZTFL1 inhibited cell proliferation, migration, invasion, and the expression of MMP9. In addition, LZTFL1 suppressed epithelial mesenchymal transition (EMT). Conclusion: Taken together, our results highlight the tumor suppressive role of LZTFL1 in HCC, suggesting that LZTFL1 may represent a potential therapeutic strategy for treating patients with HCC.

microRNA-21 promotes breast cancer proliferation and metastasis by targeting LZTFL1

Background

Breast cancer is the most common cancer type in female. As microRNAs play vital role in breast cancer, this study aimed to explore the molecular mechanism and clinical value of miR-21 in breast cancer.

Methods

qRT-PCR was performed to detect miR-21 levels in plasma of 127 healthy controls, 82 benign breast tumor, 252 breast cancer patients, as well as in breast cancer cell lines. Transwell and wound healing assay were used to analyze breast cancer metastasis in response to miR-21 inhibitor. Colony formation and eFluor™ 670 based flow cytometric analysis were used to test breast cancer proliferation following miR-21 inhibitor treatment. Leucine zipper transcription factor-like 1 (LZTFL1), the target gene of miR-21 was predicted by MIRDB, TargetScan 5.1, PicTar and miRanda. Survival analysis of LZTFL1 levels in breast cancer prognosis was estimated with the Kaplan–Meier method by log-rank test according to data from the Cancer Genome Atlas. Luciferase activity assay was performed to confirm the regulation of miR-21 on LZTFL1. LZTFL1 siRNA and miR-21 inhibitor were co-transfected to breast cancer cells, then cell proliferation, migration and epithelial–mesenchymal transition (EMT) makers were tested. BALB/c nude mice were injected in situ with Hs578T cells stably overexpressing miR-21. Breast tumor growth, metastasis and the expression of EMT markers or LZTFL1 were detected in vivo.

Results

Plasma miR-21 levels were elevated in breast cancer patients compared with healthy controls and benign breast tumor patients, and the miR-21 levels were significantly decreased after surgery comparing with pre operation in 44 patients. Inhibition of miR-21 suppressed cell proliferation and metastasis in breast cancer cells. LZTFL1 was identified as a novel target gene of miR-21. Knockdown of LZTFL1 overcame the suppression of miR-21 inhibitor on cell proliferation, metastasis and the expression of EMT markers in breast cancer cells. miR-21 overexpression promoted breast cancer cell proliferation and metastasis in vivo.

Conclusions

These results indicate that plasma miR-21 level is a crucial biomarker for breast cancer diagnosis and targeting miR-21–LZTFL1–EMT axis might be a promising strategy in breast cancer therapy.

Trial registration

Retrospectively registered.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5951-3) contains supplementary material, which is available to authorized users.

Molecular Characterization and Functional Analysis of Leucine Zipper Transcription Factor Like 1 in Zebrafish (Danio rerio)

Leucine zipper transcription factor like 1 (LZTFL1) is a member of the Bardet-Biedl syndrome gene family. LZTFL1-null mice show the phenotype of obesity, retinal degeneration, and abnormal cilia development. Functionally, LZTFL1 serves as a tumor suppressor and a negative regulator in the hedgehog signaling pathways. The biological function of mammalian LZTFL1 is partially addressed, but data on other model organisms are limited. Zebrafish (Danio rerio) is widely considered as a powerful model to understand the functions of genes implicated in obesity, disease, and cancer. In this study, LZTFL1 homologs were identified in zebrafish (zebrafish LZTFL1). The full-length cDNA of zebrafish LZTFL1 contained 897 bps encoding 298 amino acids. Zebrafish LZTFL1 displayed conserved domains of coil-coil and leucine zipper domain. PCR results showed that zebrafish LZTFL1 was widely distributed in various tissues. Western blot analysis further revealed that zebrafish LZTFL1 was detected to be ectopically expressed in HeLa cells with correct molecular weight. Fluorescence images showed as well that zebrafish LZTFL1 was localized in the cytoplasm. Furthermore, luciferase reporter assay indicated zebrafish LZTFL1 served as a negative regulator in the hedgehog signaling pathway. These data supported that zebrafish was a good model for understanding the biological roles of LZTFL1.

IGF-1-induced MMP-11 expression promotes the proliferation and invasion of gastric cancer cells through the JAK1/STAT3 signaling pathway

The present study aimed to investigate the association between insulin-like growth factor-1 (IGF-1) and matrix metalloproteinase-11 (MMP-11) expression in gastric cancer (GC) and the underlying mechanisms in SGC-7901 cells. Reverse transcription-quantitative polymerase chain reaction analysis revealed that the expression of IGF-1 and MMP-11 was significantly upregulated in GC tissues compared with normal gastric tissue. Furthermore, IGF-1 significantly and dose-dependently promoted MMP-11. Western blotting revealed that the addition of IGF-1 to SGC-7901 cells led to an evident enhancement in signal transducer and activator of transcription 3 (STAT3), IGF-1R and Janus kinase 1 (JAK1) phosphorylation at 20 and 40 min. A decrease in the extent of the elevated expression of MMP-11 and the enhanced phosphorylation of STAT3, JAK1 and IGF-1 receptor (IGF-1R) induced by IGF-1 in SGC-7901 cells were observed following treatment with NT157 (an IGF-1R inhibitor). Furthermore, piceatannol (a JAK1 inhibitor) or small interfering RNA against STAT3 reduced the extent of the increased expression of MMP-11 induced by IGF-1 in SGC-7901 cells. Piceatannol treatment induced the dose-dependent decline in the enhancement of STAT3 phosphorylation induced by IGF-1, indicating that the JAK1/STAT3 pathway may be implicated in the elevated expression of MMP-11 induced by IGF-1 in SGC-7901 cells. Finally, IGF-1 treatment significantly promoted the proliferation and invasion of SGC-7901 cells, which was inhibited following NT157, piceatannol or si-STAT3 treatment. The present study therefore demonstrated that IGF-1-induced MMP-11 may have facilitated the proliferation and invasion of SGC-7901 cells via the JAK1/STAT3 pathway.

UBE2T promotes nasopharyngeal carcinoma cell proliferation, invasion, and metastasis by activating the AKT/GSK3β/β-catenin pathway

Increasing evidence has shown that UBE2T plays an important role in genomic integrity and carcinogenesis; however, its role in nasopharyngeal carcinoma (NPC) has not been investigated. Here, we evaluated the clinicopathological significance of UBE2T in NPC and its underlying mechanisms. Using immunohistochemical analysis of UBE2T expression in NPC samples, we demonstrated that UBE2T is highly expressed in NPC tissues, which correlated with the T/M classification, skull invasion, and poor prognosis. The in vitro assay showed that UBE2T overexpression promoted proliferation, migration, and invasion of NPC cells, while UBE2T knockdown inhibited these processes. Consistent with our in vitro results, in vivo studies indicated that UBE2T overexpression promoted the growth of NPC xenografts and NPC cell metastasis. We found that UBE2T overexpression activated, whereas UBE2T knockdown inhibited, the AKT/GSK3β/β-catenin pathway. Moreover, the pathway-activation and in vitro pro-metastasis effects of UBE2T were blocked by the AKT inhibitor, MK-2206 2HCl. Additionally, UBE2T and p-GSK3 β co-expressed in NPC samples by serial section, and their expressions are correlated. Collectively, our findings demonstrated that UBE2T is a possible diagnostic/prognostic biomarker for NPC and may promote the development and progression of NPC by activating the AKT/GSK3β/β-catenin pathway. Thus, UBE2T could serve as an alternative target for the treatment of NPC.

The regulation of β-catenin activity and function in cancer: therapeutic opportunities

Wnt/β-catenin signaling is an evolutionarily conserved and versatile pathway that is known to be involved in embryonic development, tissue homeostasis and a wide variety of human diseases. Aberrant activation of this pathway gives rise to the accumulation of β-catenin in the nucleus and promotes the transcription of many oncogenes such as c-Myc and CyclinD-1. As a result, it contributes to carcinogenesis and tumor progression of several cancers, including colon cancer, hepatocellular carcinoma, pancreatic cancer, lung cancer and ovarian cancer. β-Catenin is a pivotal component of the Wnt signaling pathway and it is tightly regulated at three hierarchical levels: protein stability, subcellular localization and transcriptional activity. Uncovering the regulatory mechanisms of β-catenin will provide new insights into the pathogenesis of cancer and other diseases, as well as new therapeutic strategies against these diseases. In this review we dissect the concrete regulatory mechanisms of β-catenin from three aspects mentioned above. Then we focus on the role of β-catenin in cancer initiation, progression, dormancy, immunity and cancer stem cell maintenance. At last, we summarize the recent progress in the development of agents for the pharmacological modulation of β-catenin activity in cancer therapy.

miR-106b-5p promotes renal cell carcinoma aggressiveness and stem-cell-like phenotype by activating Wnt/β-catenin signalling

PURPOSE

To examine the role of miR-106b-5p in regulating the cancer stem-cell-like phenotype in clear cell renal cell carcinomas (ccRCC).

EXPERIMENTAL DESIGN

Real-time PCR was performed to evaluate miR-106b-5p levels in ccRCC cell lines and patients specimens. A series of in vivo and in vitro assays were performed to confirm the effect of miR-106b-5p on ccRCC stemness phenotype.

RESULTS

ccRCC cells and tissues expressed more miR-106b-5p than normal controls. Gain- and loss-of-function studies demonstrated that overexpression of miR-106b-5p in ccRCC cells increased the spheres formation ability and the proportion of side population cells. Ectopic expression of miR-106b-5p in ccRCC cells increased tumour growth rates and the number of metastatic colonies in the lungs by using an orthotopic kidney cancer model and a tail vein injection model, respectively. Mechanistic studies revealed that, miR-106b-5p has an activating effect on Wnt/β-catenin signalling. miR-106p-5p overexpression simultaneously targets multiple negative regulators of the Wnt/β-catenin pathway, namely, LZTFL1, SFRP1 and DKK2. In addition, we also confirmed that miR-106b-5p and its targets expression correlates with the overall-survival of ccRCC patients from TCGA.

CONCLUSIONS

These findings suggest that miR-106b-5p mediates the constitutive activation of Wnt/β-catenin signalling, likely serving as a potential therapeutic target for ccRCC.

Interaction between Wnt/β-catenin pathway and microRNAs regulates epithelial-mesenchymal transition in gastric cancer (Review)

Gastric cancer (GC) is the third primary cause of cancer-related mortality and one of the most common type of malignant diseases worldwide. Despite remarkable progress in multimodality therapy, advanced GC with high aggressiveness always ends in treatment failure. Epithelial-mesenchymal transition (EMT) has been widely recognized to be a key process associating with GC evolution, during which cancer cells go through phenotypic variations and acquire the capability of migration and invasion. Wnt/β-catenin pathway has established itself as an EMT regulative signaling due to its maintenance of epithelial integrity as well as tight adherens junctions while mutations of its components will lead to GC initiation and diffusion. The E-cadherin/β-catenin complex plays an important role in stabilizing β-catenin at cell membrane while disruption of this compound gives rise to nuclear translocation of β-catenin, which accounts for upregulation of EMT biomarkers and unfavorable prognosis. Additionally, several microRNAs positively or negatively modify EMT by reciprocally acting with certain target genes of Wnt/β-catenin pathway in GC. Thus, this review centers on the strong associations between Wnt/β-catenin pathway and microRNAs during alteration of EMT in GC, which may induce advantageous therapeutic strategies for human gastric cancer.

Hydrogen Sulfide Inhibits Transforming Growth Factor-β1-Induced EMT via Wnt/Catenin Pathway

Hydrogen sulfide (H2S) has anti-fibrotic potential in lung, kidney and other organs. The exogenous H2S is released from sodium hydrosulfide (NaHS) and can influence the renal fibrosis by blocking the differentiation of quiescent renal fibroblasts to myofibroblasts. But whether H2S affects renal epithelial-to-mesenchymal transition (EMT) and the underlying mechanisms remain unknown. Our study is aimed at investigating the in vitro effects of H2S on transforming growth factor-β1 (TGF-β1)-induced EMT in renal tubular epithelial cells (HK-2 cells) and the associated mechanisms. The induced EMT is assessed by Western blotting analysis on the expressions of α-SMA, E-cadherin and fibronectin. HK-2 cells were treated with NaHS before incubating with TGF-β1 to investigate its effect on EMT and the related molecular mechanism. Results demonstrated that NaHS decreased the expression of α-SMA and fibronectin, and increased the expression of E-cadherin. NaHS reduced the expression of TGF-β receptor type I (TβR I) and TGF-β receptor type II (TβR II). In addition, NaHS attenuated TGF-β1-induced increase of β-catenin expression and ERK phosphorylation. Moreover, it inhibited the TGF-β1-induced nuclear translocation of ββ-catenin. These effects of NaHS on fibronectin, E-cadherin and TβR I were abolished by the ERK inhibitor U0126 or β-catenin inhibitor XAV939, or β-catenin siRNA interference. We get the conclusion that NaHS attenuated TGF-β1-induced EMT in HK-2 cells through both ERK-dependent and β-catenin-dependent pathways.

LZTFL1 suppresses lung tumorigenesis by maintaining differentiation of lung epithelial cells

Lung cancer is the leading cause of cancer-related death in the United States, and metastatic behavior is largely responsible for this mortality. Mutations in multiple ‘driver' oncogenes and tumor suppressors are known to contribute to the lung tumorigenesis and in some cases represent therapeutic targets. Leucine Zipper Transcription Factor-like 1 (LZTFL1) is located in the chromosome region 3p21.3 where allelic loss and genetic alterations occur early and frequently in lung cancers. Previously, we found that LZTFL1 is downregulated in epithelial tumors, including lung cancer, and functions as a tumor suppressor in gastric cancers. However, the functional role of LZTFL1 in lung oncogenesis is undefined. We show here that downregulation of LZTFL1 expression in non-small cell lung cancer is associated with recurrence and poor survival, whereas re-expression of LZTFL1 in lung tumor cells inhibited extravasation/colonization of circulating tumor cells to the lung and inhibited tumor growth in vivo. Mechanistically, we found that LZTFL1 is expressed in ciliated human bronchial epithelial cells (HBECs) and its expression correlates with HBEC differentiation. LZTFL1 inhibits transforming growth factor β-activated mitogen-activated protein kinase and hedgehog signaling. Alteration of intracellular levels of LZTFL1 resulted in changes of expression of genes associated with epithelial-to-mesenchymal transition (EMT). We conclude that LZTFL1 inhibits lung tumorigenesis, possibly by maintaining epithelial cell differentiation and/or inhibition of signalings that lead to EMT and suggest that reactivation of LZTFL1 expression in tumor cells may be a novel lung cancer therapeutic approach.