14-3-3ζ promotes lung cancer cell invasion by increasing the Snail protein expression through atypical protein kinase C (aPKC)/NF-κB signaling

Targeting enolase 1 reverses bortezomib resistance in multiple myeloma through YWHAZ/Parkin axis

BACKGROUND

Enolase 1 (ENO1) is a conserved glycolytic enzyme that regulates glycolysis metabolism. However, its role beyond glycolysis in the pathophysiology of multiple myeloma (MM) remains largely elusive. Herein, this study aimed to elucidate the function of ENO1 in MM, particularly its impact on mitophagy under bortezomib-induced apoptosis.

METHODS

The bone marrow of clinical MM patients and healthy normal donors was used to compare the expression level of ENO1. Using online databases, we conducted an analysis to examine the correlation between ENO1 expression and both clinicopathological characteristics and patient outcomes. To investigate the biological functions of ENO1 in MM and the underlying molecular mechanisms involved, we conducted the following experiment: construction of a subcutaneous graft tumor model, co-immunoprecipitation, western blot, quantitative real-time polymerase chain reaction, immunohistochemistry, flow cytometry, and cell functional assays.

RESULTS

ENO1 was identified as an unfavorable prognostic factor in MM. ENO1 knockdown suppresses tumorigenicity and causes cell cycle arrest. Inhibition of ENO1-regulated mitophagy sensitizes tumor cells to apoptosis. ENO1 enhanced the stability of the YWHAZ protein by increasing the acetylation of lysine in YWHAZ while antagonizing its ubiquitination, which in turn promoted mitophagy. HDAC6 mediates the deacetylation of YWHAZ by deacetylating the K138 site of YWHAZ. Inhibition of HDAC6 increased YWHAZ acetylation and decreased YWHAZ ubiquitination. Furthermore, combination treatment with bortezomib and pharmaceutical agents targeting ENO1 has synergistic anti-MM effects both in vivo and in vitro.

CONCLUSION

Our data suggest that ENO1 promotes MM tumorigenesis and progression. ENO1 activates mitophagy by promoting the stability of YWHAZ and inhibits apoptosis and thus, leads to the drug resistance. ENO1-dependent mitophagy promotes MM proliferation and suppresses the level of bortezomib-induced apoptosis. Inhibition of ENO1 may represent a potential strategy to reverse the resistance of MM to bortezomib.

MicroRNA-185-5p targets tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta to regulate non-small cell lung cancer progression

BACKGROUND

Lung cancer (LC) is one of the most frequent cancers worldwide, as well as the leading cause of cancer-related death. Non-small cell lung cancer (NSCLC, which accounts for 85% of occurrences) is the main type of LC. MiRNAs appear to play a role in the occurrence and progression of many malignancies, according to mounting data. The underlying mechanism of miRNAs in regulating NSCLC cell biological activity and progression, on the other hand, is still being investigated.

METHODS

QRT-PCR were used to detect miR-185-5p expression and YWHAZ mRNA in NSCLC. The CCK-8 assay was used to determine the tumor cells' ability to proliferate. Transwall assay was used to test the migratory and invasive properties of cells. Cell apoptosis was detected using flow cytometry. Tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ), E-Cadherin, N-Cadherin and cleaved-caspase3 protein expression were assessed using Western Blot. The bioinformatics analysis software StarBase2.0 predicted miR-185-5p downstream targets. To confirm the target association between miR-185-5p and YWHAZ, a luciferase experiment was used. In addition, an NCl-H1299 xenograft model was created to assess the anti-tumor impact of miR-185-5p in vivo. The expression level of YWHAZ in tumor tissues of small xenograft tumor model was detected by immunohistochemistry assay.

RESULTS

Decreased miR-185-5p expression levels were observed in NSCLC. In vitro, over-expressed miR-185-5p decreased cell viability, proliferation, invasion/migration, and induced cell apoptosis, while inhibiting tumor growth in vivo. Dual-luciferase gene experiments confirmed that YWHAZ binds to miR-185-5p. Overexpression of YWHAZ partially restored the inhibitory effects of miR-185-5p on cell behaviors.

CONCLUSION

MiR-185-5p was down-regulated in NSCLC, and that overexpressed miR-185-5p inhibited malignant behaviors of cells and tumor growth by negatively regulating YWHAZ.

The effects of the prognostic biomarker SAAL1 on cancer growth and its association with the immune microenvironment in lung adenocarcinoma

BACKGROUND

Inhibition of Serum Amyloid A-like 1 (SAAL1) expression could inhibit cancer progression and improve the prognosis of cancer patients. At present, the correlation between SAAL1 and lung adenocarcinoma (LAC) remains unclear. Therefore, this study surveyed the worth and pathway of SAAL1 in LAC progression and immunity.

METHODS

Bioinformatics and immunohistochemistry were used to identify the SAAL1 expression in LAC. The roles of SAAL1 expression in the existence values of LAC patients were explored, and the nomograms were constructed. Clinical values of SAAL1 co-expressed genes were evaluated by COX regression, survival, and Receiver operating characteristic (ROC) analysis. EDU and western blotting methods were used to inquiry the functions and pathways of the SAAL1 in cell growths. The correlation between the SAAL1 level and immune microenvironment was visualized using correlation research.

RESULTS

SAAL1 level was elevated in LAC tissues, and was observed in cancer tissues of dead patients. SAAL1 overexpression had something to do with shorter overall survival, progression-free interval, and disease-specific survival in LAC. The area under the curve of SAAL1 was 0.902 in normal tissues and cancer tissues. Inhibition of SAAL1 expression could inhibit cancer cell proliferation, which may be related to the decreased expression of cyclin D1 and Bcl-2 proteins. In LAC, SAAL1 level had something to do with stromal, immune, and estimate scores, and correlated with macrophages, T cells, Th2 cells, CD8 T cells, NK CD56dim cells, DC, eosinophils, NK CD56bright cells, pDC, iDC, cytotoxic cells, Tgd, aDC cells, B cells, Tcm, and TFH levels. SAAL1 overexpression had something to do with existence values and the immunity in LAC.

CONCLUSIONS

Inhibition of SAAL1 expression could regulate cancer growth via cyclin D1 and Bcl-2. SAAL1 is a promising prognostic biomarker in LAC patients.

Loss of ubiquitin-specific peptidase 18 destabilizes 14-3-3ζ protein and represses lung cancer metastasis

Cancer metastasis is a major cause of cancer-related mortality. Strategies to reduce metastases are needed especially in lung cancer, the most common cause of cancer mortality. We previously reported increased ubiquitin-specific peptidase 18 (USP18) expression in lung and other cancers. Engineered reduction of USP18 expression repressed lung cancer growth and promoted apoptosis. This deubiquitinase (DUB) stabilized targeted proteins by removing the complex interferon-stimulated gene 15 (ISG15). This study explores if the loss of USP18 reduced lung cancer metastasis. USP18 knock-down in lung cancer cells was independently achieved using small hairpin RNAs (shRNAs) and small interfering RNAs (siRNAs). USP18 knock-down reduced lung cancer growth, wound-healing, migration, and invasion versus controls (P < .001) and markedly decreased murine lung cancer metastases (P < .001). Reverse Phase Protein Arrays (RPPAs) in shRNA knock-down lung cancer cells showed that 14-3-3ζ protein was regulated by loss of USP18. ISG15 complexed with 14-3-3ζ protein reducing its stability. Survival in lung adenocarcinomas (P < .0015) and other cancers was linked to elevated 14-3-3ζ expression as assessed by The Cancer Genome Atlas (TCGA). The findings were confirmed and extended using 14-3-3ζ immunohistochemical assays of human lung cancer arrays and syngeneic murine lung cancer metastasis models. A direct 14-3-3ζ role in controlling lung cancer metastasis came from engineered 14-3-3ζ knock-down in lung cancer cell lines and 14-3-3ζ rescue experiments that reversed migration and invasion inhibition. Findings presented here revealed that USP18 controlled metastasis by regulating 14-3-3ζ expression. These data provide a strong rationale for developing a USP18 inhibitor to combat metastases.

hsa-MicroRNA-28-5p Inhibits Diffuse Large B-Cell Lymphoma Cell Proliferation by Downregulating 14-3-3ζ Expression

MicroRNAs (miRNAs) participate in the comprehensive biological process of several cancer types. In our former study, we found that hsa-microRNA- (miR-)28-5p was downregulated, but tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activating protein zeta (14-3-3ζ or YWHAZ) was upregulated in diffuse large B-cell lymphoma (DLBCL) tissues. We predicted that YWHAZ was a target gene for hsa-miR- 28-5p using bioinformatics analysis. Our goal was to reveal the role of hsa-miR-28-5p in DLBCL. YWHAZ was tested by immunohistochemistry (IHC) in formalin-fixed paraffin-embedded (FFPE) tissues of 137 DLBCL tissues, and the expression of hsa-miR-28-5p and YWHAZ was examined by quantitative real-time polymerase chain reaction (qRT-PCR) in 15 fresh and frozen DLBCL tissues. To study the functional roles of the downregulated hsa-miR-28-5p in DLBCL, a Cell Counting Kit-8 assay was conducted to estimate cell proliferation. Transient transfection of miRNA mimics was performed to overexpress hsa-miR-28-5p, and flow cytometry was performed to examine cell apoptosis and cell cycle progression. A dual-luciferase reporter assay was employed to explore the relationship between hsa-miR-28-5p and YWHAZ. Western blotting and qRT-PCR were used to investigate the function of hsa-miR-28-5p in YWHAZ expression. hsa-miR-28-5p was found to be significantly downregulated in DLBCL tissues and cell lines. Functional studies showed that hsa-miR-28-5p overexpression inhibited cell viability and proliferation, and YWHAZ was predicted to be a target of hsa-miR-28-5p. Dual-luciferase reporter assay, Western blotting, and qRT-PCR verified that hsa-miR-28-5p negatively regulated YWHAZ expression by directly targeting its 3′ untranslated regions in DLBCL cells. hsa-miR-28-5p may suppress the growth of DLBCL cells by inhibiting YWHAZ expression. These findings could provide novel targets for DLBCL diagnosis and therapy.

14-3-3η Promotes Invadosome Formation via the FOXO3-Snail Axis in Rheumatoid Arthritis Fibroblast-like Synoviocytes

Erosive destruction of joint structures is a critical event in the progression of rheumatoid arthritis (RA), in which fibroblast-like synoviocytes (FLS) are the primary effectors. We previously reported that the ability of RA FLS to degrade extracellular matrix (ECM) components depends on the formation of actin-rich membrane protrusions, called invadosomes, through processes that remain elusive. 14-3-3η belongs to a family of scaffolding proteins involved in a wide range of cellular functions, and its expression is closely related to joint damage and disease activity in RA patients. In this study, we sought to assess the role of 14-3-3η in joint damage by examining its contribution to the invadosome formation phenotype of FLS. Using human primary FLS, we show that 14-3-3η expression is closely associated with their ability to form invadosomes. Furthermore, knockdown of 14-3-3η using shRNAs decreases the level of invadosome formation in RA FLS, whereas addition of the recombinant protein to FLS from healthy individuals promotes their formation. Mechanistic studies suggest that 14-3-3η regulates invadosome formation by increasing Snail expression, a mechanism that involves nuclear exclusion of the transcription repressor FOXO3. Our results implicate the 14-3-3η–FOXO3–Snail axis in promoting the aggressive ECM-degrading phenotype of RA FLS, and suggest a role for this scaffolding protein in cartilage degradation.

14-3-3ζ promoted invasion and lymph node metastasis of breast invasive ductal carcinoma with HER2 overexpression

BACKGROUND

HER2 was a recognized oncogene that promoted the development and metastasis of breast cancer, but its positive expression rate in invasive ductal carcinoma (IDC) was much lower than that in ductal carcinoma in situ (DCIS). The correlation between the occurrence and development of breast cancer and the amplification and overexpression of HER2 gene alone was still controversial. 14-3-3ζ had a strong protein binding ability and a variety of functions, mainly through the interaction with other proteins to exert its unique biological activities. However, influence and interaction relationship of the two proteins on the development of IDC was not clear. Furthermore, the mutual effect mechanism of synergy effect on lymph node metastasis of IDC was not known well too.

METHODS

Immunohistochemistry experiment was performed to detect expression status of 14-3-3ζ, HER2, TGF-β, p53 and Gli2 in paraffin-embedded samples respectively, including 30 cases of normal breast tissue, 30 cases of usual ductal hyperplasia (UDH), 30 cases of atypical ductal hyperplasia (ADH), 30 cases of DCIS and 120 cases of IDC.

RESULTS

The positive expression rates of 14-3-3ζ/HER2 in Normal group, UDH group, ADH group, DCIS group and IDC group were 30%/0.00%, 26.7%/0.00%, 53.3%/33.3%, 46.7%/53.3% and 50%/24.2%, respectively. Compared with Normal group or UDH group, the expression of 14-3-3ζ was significantly increased in ADH, DCIS and IDC groups. 14-3-3ζ was overexpressed in only 4 of the 16 DCIS cases with HER2 overexpression (25.0%, 4/16), but it was overexpressed in 7 of the 9 IDC cases with DCIS (77.8%, 7/9). Among HER2 overexpression cases, 14-3-3ζ overexpression was significantly different between DCIS group and IDC with DCIS group (P = 0.017). In 18 IDC cases with lymph node metastasis and HER2 overexpression, 14-3-3ζ was overexpressed in 15 cases (83.3%, 15/18), while in the 11 IDC cases without lymph node metastasis, 14-3-3ζ and HER2 were overexpressed in only 5 cases (45.5%, 5/11). Co-overexpression of 14-3-3ζ and HER2 was positively correlated with occurrence of lymph node metastasis (P = 0.048). TGF-β was overexpressed in both precancerous lesion group and IDC group compared with normal group. Compared with the IDC group without lymph node metastasis, TGF-β expression was significantly increased in the IDC group with lymph node metastasis (P = 0.015). In IDC cases with 14-3-3ζ and HER2 co-overexpression, the expression of p53 in IDC with lymph node metastasis was significantly decreased (P = 0.010), while the expression of Gli2 was significantly increased compared with IDC cases without lymph node metastasis (P = 0.038). The co-overexpression of 14-3-3ζ and HER2 was positively correlated with ER negative expression (P < 0.001) and PR negative expression (P = 0.038), respectively.

CONCLUSION

14-3-3ζ synergistic with HER2 could promote the occurrence and development of breast IDC and induce the lymph node metastasis of IDC, suggesting that combined overexpression of 14-3-3ζ and HER2 would lead to higher invasion and metastasis risk of breast cancer. It was speculated that the combined detection of 14-3-3ζ and HER2 would be one of the key factors affecting the clinical treatment decision and prognosis.

Development and validation of a novel epigenetic-related prognostic signature and candidate drugs for patients with lung adenocarcinoma

Background: Epigenetic dysregulation has been increasingly proposed as a hallmark of cancer. Here, the aim of this study is to establish an epigenetic-related signature for predicting the prognosis of lung adenocarcinoma (LUAD) patients.

Results: Five epigenetic-related genes (ERGs) (ARRB1, PARP1, PKM, TFDP1, and YWHAZ) were identified as prognostic hub genes and used to establish a prognostic signature. According our risk score system, LUAD patients were stratified into high and low risk groups, and patients in the high risk group had a worse prognosis. ROC analysis indicated that the signature was precise in predicting the prognosis. A new nomogram was constructed based on the five hub genes, which can predict the OS of every LUAD patients. The calibration curves showed that the nomogram had better accuracy in prediction. Finally, candidate drugs that aimed at hub ERGs were identified, which included 47 compounds.

Conclusions: Our epigenetic-related signature nomogram can effectively and reliably predict OS of LUAD patients, also we provide precise targeted chemotherapeutic drugs.

Methods: The genomic data and clinical data of LUAD cohort were downloaded from the TCGA database and ERGs were obtained from the EpiFactors database. GSE31210 and GSE50081 microarray datasets were included as independent external datasets. Univariate Cox, LASSO regression, and multivariate Cox analyses were applied to construct the epigenetic-related signature.

Targeting 14-3-3ζ Overcomes Resistance to Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitors in Lung Adenocarcinoma via BMP2/Smad/ID1 Signaling

Background: The 14-3-3ζ protein, which acts as a putative oncoprotein, has been found to promote the proliferation, metastasis, and chemoresistance of cancer cells in several cancers including lung adenocarcinoma (LUAD); however, its significance in epidermal growth factor receptor–tyrosine kinase inhibitor (EGFR-TKI) resistance remains unknown.

Methods: The Cancer Genome Atlas (TCGA) database was used to determine 14-3-3ζ expression in pancancer and LUAD. 14-3-3ζ and ID1 expression was then examined in clinical LUAD samples by immunohistochemistry (IHC). Lentiviral transfection with 14-3-3ζ-specific small hairpin RNA (shRNA) was used to establish stable 14-3-3ζ knockdown gefitinib-resistant PC9 (PC9/GR) and H1975 cell lines. The effect of 14-3-3ζ knockdown on reversing EGFR-TKI resistance was determined in vitro by Cell Counting Kit-8 (CCK-8), wound healing, Transwell assays, and flow cytometry. A xenograft tumor model was established to evaluate the role of 14-3-3ζ in EGFR-TKI resistance. Microarray analysis results showed multiple pathways regulated by 14-3-3ζ-shRNA.

Results: In the present study, we demonstrated that based on the TCGA, pancancer and LUAD 14-3-3ζ expression was elevated and predicted unfavorable prognosis. In addition, high 14-3-3ζ expression was associated with advanced T stage, TNM stage, presence of lymph node metastasis and, importantly, poor treatment response to EGFR-TKIs in LUAD patients with EGFR-activating mutations. 14-3-3ζ shRNA sensitized EGFR-TKI-resistant human LUAD cells to gefitinib and reversed epithelial-to-mesenchymal transition (EMT). After 14-3-3ζ depletion, bone morphogenetic protein (BMP) signaling activation was decreased in EGFR-TKI-resistant cells in microarray analysis, which was further validated by Western blot analysis. Furthermore, the expression of 14-3-3ζ positively correlates with ID1 expression in human EGFR-mutant LUAD patient samples. In vivo, there was a reduction in the tumor burden in mice treated with 14-3-3ζ shRNA and gefitinib compared to mice treated with gefitinib alone.

Conclusion: Our work uncovers a hitherto unappreciated role of 14-3-3ζ in EGFR-TKI resistance. This study might provide a potential therapeutic approach for treating LUAD patients harboring EGFR mutations.

Induction of proliferative and mutagenic activity by benzo(a)pyrene in PC-3 cells via JAK2/STAT3 pathway

Environmental carcinogen benzo(a)pyrene (BaP) is a representative compound of polycyclic aromatic hydrocarbons (PAHs). BaP is strongly associated with prostate carcinogenesis. However, the molecular mechanism of BaP in development of prostate carcinoma remains largely unknown. The aim of this study was to investigate the effect and mechanism of BaP on the development in prostate cancer. PC-3 cells were exposed to different concentrations of BaP for 24, 48, 72 h, respectively. We analyzed the effect of BaP on PC-3 cell viability, cell cycle, DNA strand breaks, mutagenic activity, and migration. The expression of associated regulatory genes and the effect of JAK2/STAT3 signaling were also measured to explore the relationships among BaP metabolism, the JAK2/STAT3 pathway and proliferative activity in PC-3 cells. We observed significant effects on proliferation, DNA strand breaks and mutagenic activity after BaP exposure in PC-3 cells, and inhibitors of CYP1 and the AhR transcription factor α -naphthoflavone (ANF) and CH223191 treatment clearly reduced both cell survival and mutagenesis associated with BaP exposure. Reduction in G0-G1 phase population and elevation in S phase were observed after BaP exposure. Migratory cells for PC-3 were significantly increased. The results were further confirmed by the expression of mRNA levels in the significant increments of Snail, Slug, MMP-9, CYP1A1, CYP1B1, CycilnD1, CDK4 and significant reduction of E-cadherin. Significant enhancements were found in the expression of JAK2, STAT3 after BaP treatment. Additionally, activator IL-6 significantly enhanced the effect of BaP on cell survival, mutagenic activity, Cyclin D1, CDK4, Snail, and JAK2/STAT3 expression in PC-3 cells. Significant reductions in cell survival, mutagenic activity, Cyclin D1, CDK4, Snail, and JAK2/STAT3 expression were found after inhibitor AG490, ANF and CHJ223191 treatment. These findings reveal that BaP enhances the proliferative and mutagenic activity via JAK2-STAT3 pathway in PC-3 cells, and provide the additional evidence to understand the crucial role of BaP in prostate cancer carcinogenesis.

The role of YWHAZ in cancer: A maze of opportunities and challenges

YWHAZ (also named 14-3-3ζ) is a central hub protein for many signal transduction pathways and plays a significant role in tumor progression. Accumulating evidences have demonstrated that YWHAZ is frequently up-regulated in multiple types of cancers and acts as an oncogene in a wide range of cell activities including cell growth, cell cycle, apoptosis, migration, and invasion. Moreover, YWHAZ was reported to be regulated by microRNAs (miRNAs) or long non-coding RNAs and exerted its malignant functions by targeting downstream molecules like protein kinase, apoptosis proteins, and metastasis-related molecules. Additionally, YWHAZ may be a potential biomarker of diagnosis, prognosis and chemoresistance in several cancers. Targeting YWHAZ by siRNA, shRNA or miRNA was reported to have great help in suppressing malignant properties of cancer cells. In this review, we perform literature and bioinformatics analysis to reveal the oncogenic role and molecular mechanism of YWHAZ in cancer, and discuss the potential clinical applications of YWHAZ concerning diagnosis, prognosis, and therapy in malignant tumors.

Targeting Mechanoresponsive Proteins in Pancreatic Cancer: 4-Hydroxyacetophenone Blocks Dissemination and Invasion by Activating MYH14

Metastasis is complex, involving multiple genetic, epigenetic, biochemical, and physical changes in the cancer cell and its microenvironment. Cells with metastatic potential are often characterized by altered cellular contractility and deformability, lending them the flexibility to disseminate and navigate through different microenvironments. We demonstrate that mechanoresponsiveness is a hallmark of pancreatic cancer cells. Key mechanoresponsive proteins, those that accumulate in response to mechanical stress, specifically nonmuscle myosin IIA (MYH9) and IIC (MYH14), α-actinin 4, and filamin B, were highly expressed in pancreatic cancer as compared with healthy ductal epithelia. Their less responsive sister paralogs-myosin IIB (MYH10), α-actinin 1, and filamin A-had lower expression differential or disappeared with cancer progression. We demonstrate that proteins whose cellular contributions are often overlooked because of their low abundance can have profound impact on cell architecture, behavior, and mechanics. Here, the low abundant protein MYH14 promoted metastatic behavior and could be exploited with 4-hydroxyacetophenone (4-HAP), which increased MYH14 assembly, stiffening cells. As a result, 4-HAP decreased dissemination, induced cortical actin belts in spheroids, and slowed retrograde actin flow. 4-HAP also reduced liver metastases in human pancreatic cancer-bearing nude mice. Thus, increasing MYH14 assembly overwhelms the ability of cells to polarize and invade, suggesting targeting the mechanoresponsive proteins of the actin cytoskeleton as a new strategy to improve the survival of patients with pancreatic cancer. SIGNIFICANCE: This study demonstrates that mechanoresponsive proteins become upregulated with pancreatic cancer progression and that this system of proteins can be pharmacologically targeted to inhibit the metastatic potential of pancreatic cancer cells.

The survival analysis and oncogenic effects of CFP1 and 14-3-3 expression on gastric cancer

Background & aim

Gastric cancer (GC) is the third-leading cause of cancer-related deaths. We established a prospective database of patients with GC who underwent surgical treatment. In this study, we explored the prognostic significance of the expression of CFP1 and 14-3-3 in gastric cancer, by studying the specimens collected from clinical subjects.

Materials & methods

Immunohistochemistry was used to detect the expression of CFP1 and 14-3-3 in 84 GC subjects, including 73 patients who have undergone radical gastrectomy and 11 patients who have not undergone radical surgery. Survival analysis was performed by km-plot data.

Results

According to the survival analysis, we can see that the survival time of patients with high expression of CFP1 is lower than the patients with low expression in gastric cancer, while the effect of 14-3-3 is just the opposite. The survival time of patients with higher expression of 14-3-3 is also longer.

Conclusion

The CFP1 and 14-3-3 genes can be used as prognostic markers in patients with GC, but the study is still needed to confirm.

Long non-coding RNA LINC00858 promotes cells proliferation, migration and invasion by acting as a ceRNA of miR-22-3p in colorectal cancer

Though long non-coding RNA LINC00858 (LINC00858) has been shown to be involved in tumours of other tissues, its involvement in colorectal cancer (CRC) is still unknown. We aimed to investigated expression and mechanism LINC00858 in human CRC. In this study, we firstly found that LINC00858 expression was significantly up-regulated in both CRC tissues and cell lines by both online data and RT-PCR assay. Then, clinical assay revealed that high LINC00858 expression was significantly associated with advanced clinical progression and poor prognosis. Multivariate analysis demonstrated that high LINC00858 expression was an independent poor prognostic factor for CRC patients. Moreover, lost-of-function assay indicated that knockdown of LINC00858 suppressed CRC cells proliferation, migration and invasion, and promoted apoptosis. Mechanistically, bioinformatics analysis, dual-luciferase reporter assays, and western blot assays showed that LINC00858 functioned as competing endogenous RNA to repress miR-22-3p, which controlled its down-stream target YWHAZ. Then, we suggested that LINC00858 exerted its function through the miR-22-3p/YWHAZ axis. To our knowledge, this is the first report which showed the role of LINC00858 in the progression of CRC. Our findings indicated that LINC00858 played an important role in CRC, and may serve as a novel prognostic factor and therapeutic target.

Overexpression of Axl reverses endothelial cells dysfunction in high glucose and hypoxia

The receptor tyrosine kinase Axl is involved in diabetic vascular disease. This study aims to investigate the effect of high glucose on endothelial cells injury and Axl expression in hypoxia condition in vitro, and we present details of the mechanism associated with overexpression of Axl rescue the high glucose injury. Our results showed that high glucose impaired both human umbilical vein endothelial cells (HUVECs) and EAhy926 cells angiogenesis in hypoxia condition. In addition, high glucose inhibits Axl and hypoxia-inducible factor 1-α (HIF-1α) protein expression in hypoxia condition. Axl overexpression significantly reversed endothelial cells dysfunction in high glucose/hypoxia. Furthermore, Axl overexpression in EAhy926 cells increases HIF-1α protein synthesis through PI3K/Akt/mTOR/p70 ^S6K signal pathway but not Mek/Erk in high glucose/hypoxia condition. This study demonstrates that high glucose can alter Axl signaling and HIF-1α in hypoxia condition. Overexpression of Axl may rescue endothelial cells dysfunction and HIF-1α expression through its downstream signals in high glucose/hypoxia.

A two-circular RNA signature as a noninvasive diagnostic biomarker for lung adenocarcinoma

BACKGROUND

Recently, circular RNAs (circRNAs) have been reported to be microRNA sponges and play essential roles in cancer development. This study aimed to evaluate whether circulating circRNAs could be used as diagnostic biomarkers for lung adenocarcinoma (LUAD).

METHODS

The Gene Expression Omnibus (GEO) dataset was used to investigate differentially expressed circRNAs (DEcircRNAs) in paired LUAD tissues and adjacent nontumor tissues. The expression levels of the host genes were analyzed in The Cancer Genome Atlas (TCGA)-LUAD dataset, and the prognostic value was assessed using the Kaplan-Meier plotter. Quantitative real-time PCR (qRT-PCR) was performed to validate the expression of candidate circRNAs in the LUAD plasma and cells. The CCK8 assay was used to measure the function of circRNAs in cell proliferation. Competing endogenous RNA (ceRNA) network, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to predict the possible mechanisms and functions of circRNAs in LUAD.

RESULTS

Two upregulated and two downregulated circRNAs were identified as candidate circRNAs using bioinformatics analysis. qRT-PCR demonstrated that hsa_circ_0005962 was upregulated in LUAD plasma and cells, whereas hsa_circ_0086414 was downregulated. Receiver operating characteristic (ROC) curve analysis confirmed that a signature comprising the two circRNAs had good diagnostic potential, with an area under the ROC curve (AUC) of 0.81 (P < 0.0001). In addition, we observed that overexpression of plasma hsa_circ_0086414 was related to EGFR mutations (P = 0.001). Plasma hsa_circ_0005962 displayed significantly different expression before and after surgery in patients with LUAD (P < 0.0001). In vitro experiments suggested that hsa_circ_0005962 promoted LUAD cell proliferation. For future studies, we predicted the circRNA-miRNA-mRNA network for hsa_circ_0005962. Bioinformatics analysis revealed that hsa_circ_0005962 might be involved in LUAD development.

CONCLUSION

A circRNA signature was identified as a potential noninvasive biomarker for LUAD diagnosis.

miR-375-3p/YWHAZ/β-catenin axis regulates migration, invasion, EMT in gastric cancer cells

YWHAZ (14-3-3ζ) plays crucial roles in regulating proliferation, apoptosis, migration, and invasion of gastric cancer (GC) cells. However, its extensive roles and potential mechanisms in GC cells remain unknown, and need to be researched deeply. In this study, we focus on the role of miR-375/YWHAZ axis in migration, invasion and epithelial-to-mesenchymal transition (EMT) of GC cells. YWHAZ level was assessed by western blot and qPCR assays in GC cells. Scratch and transwell assays were used to determine the migration and invasion of GC cells. The protein levels of correlative molecules were detected by western blot. The regulation of miR-375 on the expression of its target gene YWHAZ was verified by dual-luciferase report system. According to the results, knockdown of YWHAZ inhibited the migration, invasion and EMT of GC cells. Moreover, silencing of YWHAZ restrained the activation of wnt/β-catenin signalling pathway. YWHAZ was confirmed to be a target gene of miR-375, and its expression was regulated by miR-375 in GC cells. Transfection of miR-375 inhibitor promoted the migration, invasion, EMT and activation of wnt/β-catenin pathway in GC cells, which was suppressed by inhibition of YWHAZ. Taken together, this study suggests that miR-375/YWHAZ axis may be served as a novel therapeutic target for GC patients.

Overexpression of 14-3-3ζ in lung tissue predicts an improved outcome in patients with lung adenocarcinoma

One of the factors limiting the survival rate of patients with lung cancer is the high risk for recurrence following surgical resection. Previous studies indicate that 14-3-3ζ is a central cellular hub protein that regulates multiple signaling pathways involved in cancer progression. The present study evaluated the prognostic significance of 14-3-3ζ in patients with lung adenocarcinoma. The expression of 14-3-3ζ and E-cadherin, an important protein involved in the epithelial-mesenchymal transition, was evaluated by immunohistochemistry in lung tumor tissues and adjacent normal lung tissues resected from 123 patients with lung adenocarcinoma. The correlation between the two proteins, their association with clinicopathological features and their prognostic significance were subsequently analyzed. Within these parameters, an overall survival (OS) prediction model was constructed using multivariate Cox proportional hazards regression. The expression of 14-3-3ζ was upregulated in lung adenocarcinoma, in contrast to E-cadherin, which was downregulated in lung adenocarcinoma tissues compared with normal tissues. In addition, the expression of 14-3-3ζ was positively correlated with that of E-cadherin (r=0.256, P=0.012) and differentiation (P<0.001). Increased E-cadherin expression was indicative of smaller tumor size and greater differentiation, and the overexpression of 14-3-3ζ and E-cadherin were associated with longer OS (P=0.010 and P=0.006, respectively). Finally, a multivariate analysis revealed that TNM stage and 14-3-3ζ were independent prognostic indicators (P<0.001 and P=0.026, respectively). 14-3-3ζ may function as a tumor suppressor associated with E-cadherin upregulation and could be used as a prognostic biomarker for resected lung adenocarcinoma. These findings provide a novel insight on potential intervention strategies for patients with lung cancer.

Knockdown of tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ) enhances tumorigenesis both in vivo and in vitro in bladder cancer

Bladder cancer is the most common tumor of the urinary tract. Tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ), a gene encoding the 14-3-3ζ protein, has been observed to be frequently amplified in bladder cancer. However, the role of 14-3-3ζ in various types of cancer is controversial. With reproduction of The Cancer Genome Atlas database, we searched the correlation of YWHAZ expression with survival outcomes of multiple cancers in silico. Our results revealed that only in bladder cancer was there a positive survival trend with YWHAZ overexpression. To study its role in bladder cancer, YWHAZ was successfully downregulated by lentivirus in 5637 and T24 cells. MTT and colony-formation assays showed that YWHAZ downregulation increased cell proliferation. Wound healing and Transwell assays showed that YWHAZ downregulation enhanced cell migration and invasiveness. FACS analysis showed that YWHAZ induced cell cycle arrest, but not apoptosis. A xenograft tumor model revealed that YWHAZ knockdown enhanced tumor growth. Gene set enrichment analysis confirmed that the cell cycle pathway plays a vital role in the function of the YWHAZ gene. In conclusion, knockdown of YWHAZ promoted both in vitro and in vivo tumorigenesis in bladder cancer and may be a novel biomarker for bladder cancer deserving further study.

Upregulation of MUC1 by its novel activator 14-3-3ζ promotes tumor invasion and indicates poor prognosis in lung adenocarcinoma

Lung adenocarcinoma (LAC) is currently the predominant histological subtype of lung cancer. Despite recent advancement in targeted therapies, the average 5-year survival rate is only 15%, highlighting the need to identify previously unrecognized molecular events that propel cancer development. Herein, we showed knockdown of 14-3-3ζ suppresses cell proliferation, migration and invasion capability of A549 and H1299 cells. MUC1 was then identified as a novel target of 14-3-3ζ protein. Overexpression of MUC1 is found to induce epithelial-mesenchymal transition and promote metastasis of lung cancer cells, while knockdown of 14-3-3ζ can completely abolish the oncogenic function of MUC1.Furthermore, we unraveled a novel mechanism that 14-3-3ζ activates NF-κB signaling pathway, and therefore enhanced MUC1/NF-κB feedback loop to upregulate MUC1 expression. From a clinical point of view, we evaluated the expression of14-3-3ζ and MUC1 in GSE68465 datasets, in which high expression of14-3-3ζ and MUC1 emerged as poor prognostic factors in LAC patients. In conclusion, we provide novel evidence that 14-3-3ζ regulates MUC1 through MUC1/NF-κB feedback loop. 14-3-3ζ and MUC1 is a promising prognostic biomarker for lung cancer patients and therapeutic targeting of 14-3-3ζ and MUC1 may be a potential treatment option for patients with LAC.

The functional significance of 14-3-3 proteins in cancer: focus on lung cancer

The 14-3-3 family proteins are phosphoserine/phosphothreonine binding proteins constituting a conserved class of proteins which are detected in all eukaryotic cells. In mammalians, 14-3-3 proteins have seven distinct isoforms (β, γ, ε, η, ζ, σ and τ/θ) which are involved in various cellular processes including signal transduction, cell cycle, cell proliferation, apoptosis, differentiation and survival. 14-3-3 proteins do not have a distinct catalytic activity and often regulate the activity, stability, subcellular localization and interactions of other proteins. The 14-3-3 family proteins function through interacting with their client proteins or facilitating the interaction of other proteins likely as adaptor proteins. The versatile functions of these proteins in the regulation of cell growth, cell division, cell death and cell migration make them candidate proteins for which an important role in cancer development could be envisioned. Indeed, analysis of cancer cell lines and tumor-derived tissues have indicated the differential abundance or post-translational modification of some 14-3-3 isoforms. In this review, we aimed to show how deregulation of 14-3-3 proteins contributes to initiation, establishment and progression of cancers with a particular emphasis on lung cancer. The role of these proteins in cancer-relevant processes including cell cycle, cell migration, cell-cell communication and programmed cell death will be discussed in detail.