GMSCs-Derived Exosome ZHX2 Improves Diabetes Nephropathy by Blocking AGEs/RAGE/NLRP3 Pathway to Inhibit Podocyte Pyroptosis and Inflammatory Response.

Women with breast cancer but without local metastasis to the axillary lymph nodes (ANN) have a good prognosis. However, 20 to 30% of patients with ANN breast cancer will still experience recurrence and distant metastases. Lymphatic invasion (LVI) is an important prognostic factor for ANN breast cancer. Therefore, LVI status was incorporated to provide a unique approach to identify novel genes related to outcome in ANN breast cancer. Gene expression microarrays were used to discriminate between tumors 1) with or without LVI (LVI+ or LVI-, respectively) and 2) from patients who experienced early recurrence (within 4 years) and those who were disease-free (for at least 10 years). Biostatistical analyses were performed to compile a list of statistically significant genes common to both comparisons. Zinc fingers and homeoboxes 1 (ZHX1) was identified as a candidate gene involved in LVI and associated with early recurrence of ANN breast cancer. Real-time RT-PCR (qPCR) was performed to quantify ZHX1 expression in a subset of cell lines and tumor samples. ZHX1 is expressed at different levels, mostly at an intermediate level in the tumors. A more network-based approach was used to examine biological pathways that may be associated with this poor prognosis. We discovered that ZHX1 may be involved in transcription, signaling, metabolism, and development, which is consistent with previous findings. ZHX1 binds to the other two members of the ZHX family, ZHX2 and ZHX3. All three members bind to the activation domain of the alpha subunit of nuclear transcription factor γ (NF-γ). NF-γ activates transcription of several genes, including the cell cycle progression gene, cell division cycle 25 homolog C (CDC25C). However, ZHX2 represses promoter activity of CDC25C, which would prevent cells from progressing into mitosis. Since ZHX1 binds to ZHX2 and NF-γ, this suggests that ZHX1 may be involved in the cell cycle. ZHX1 is significantly over-expressed in LVI+ tumors and in those from patients who experienced early recurrence of ANN breast cancer. The potential role of ZHX1 in the cell cycle may be associated with this poor prognosis. Gene and protein expression of ZHX1 and its candidate interactors are being quantified in cell lines via qPCR and Western blotting, respectively, and potential correlations examined. Immunohistochemistry is being performed on tissue microarrays to observe ZHX1 protein levels and localization and correlate with gene expression. Cell lines are being transfected via vector- or siRNA- based methods to over-express or knock down ZHX1, respectively. Alterations in tumorigenicity are being investigated via MTT proliferation and migration and/or invasion assays. Findings may aid in determining which ANN breast cancer patients may benefit from systemic therapy and identifying novel targets for cancer therapeutics. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3038. doi:10.1158/1538-7445.AM2011-3038

Zinc fingers and homeoboxes 2 (ZHX2) was found as a novel VHL substrate target, and acted as an oncogenic driver in ccRCC. However, the detailed mechanism of ZHX2 in ccRCC development remains elusive, and no research has focused on studying ZHX2 in drug resistance yet. A tissue microarray with 358 ccRCC samples was used to determine the expression of ZHX2 in ccRCC patients. VHL-deficient cell line 786-O and VHL-normal cell line CAKI-1 was used for lineage reprogramming by transfecting with lentivirus. The in vitro and in vivo experiments were performed with these new cell lines to determine the mechanism of ZHX2 in ccRCC development and drug resistance. Immunohistochemistry analysis showed that ZHX2 was not highly expressed in ccRCC tumor tissues, only 33.2% (119/358) patients have high ZHX2 expression. However, high ZHX2 was significantly associated with advanced Fuhrman grade (p = 0.004), and proved to be an independent prognosis factor for progression-free survival (p = 0.0003), while there is no significant correlation with overall survival. We further discovered that ZHX2 overexpression could increase VEGF secretion and transcriptional activate the MEK/ERK1/2 and promote its downstream targets. We also found ZHX2 overexpression induce Sunitinib resistance though activating autophagy and the combination treatment of Sunitinib and Chloroquine could significantly rescue the phenomenon. In summary, these results indicate that ZHX2 drivers cell growth, migration though increase VEGF expression, and transcriptional activate MEK/ERK1/2 signaling pathway, and could induce Sunitinib resistance by regulating self-protective autophagy, these may provide new insight in advanced ccRCC treatment.

Background: Triple-negative breast cancer (TNBC) is an aggressive and highly lethal disease in women, while the oncogenic mechanisms which contribute to TNBC development, progression, and metastasis are poorly investigated and therefore warrant the critical need to identify novel oncogenic signalings and develop new therapeutic targets. Results: We show that Zinc Fingers and Homeoboxes 2 (ZHX2) is amplified or overexpressed in TNBC cell lines and patients. Functionally, depletion of ZHX2 inhibited TNBC cell growth and invasion in vitro, orthotopic tumor growth, and spontaneous lung metastasis in vivo. Mechanistically, ZHX2 bound with hypoxia-inducible factor (HIF) family members and positively regulated HIF1α protein level and activity in TNBC. Integrated ChIP-seq and gene expression profiling demonstrated that ZHX2 co-occupied with HIF1α on transcriptionally active promoters marked by H3K4me3 and H3K27ac, thereby promoting gene expression. Among the identified ZHX2 and HIF1α coregulated genes, overexpression of AP2B1, COX20, KDM3A, or PTGES3L could partially rescue TNBC cell growth defect by ZHX2 depletion, suggesting that these downstream targets contribute to the oncogenic role of ZHX2 in an accumulative fashion. Furthermore, multiple residues (R491, R581, and R674) on ZHX2 are important in regulating its phenotype, which correspond with their roles in controlling ZHX2 transcriptional activity in TNBC cells. These studies establish that ZHX2 activates oncogenic HIF1α signaling, therefore serving as a potential therapeutic target for TNBC. Conclusion: ZHX2 has been highlighted as one critical hypoxia-related factors regulator contributing to triple-negative breast cancer in this work, which has enriched the upstream regulatory network of HIF-1α signaling. Moreover, identification of key residuals determining biological function of ZHX2 provides novel approaches for treating TNBC via targeting the hypoxia pathway. Citation Format: Chengheng Liao, Wentong Fang, Rachel Shi, Jeremy Simon, Travis Ptacek, Giada Zurlo, Youqiong Ye, Leng Han, Cheng Fan, Lei Bao, Christopher Llynard Ortiz, Hong-Rui Lin, Ujjawal Manocha, Weibo Luo, Yan Peng, William Y Kim, Lee-Wei Yang, Qing Zhang. ZHX2 promotes HIF1α oncogenic signaling in triple-negative breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-08-23.

Triple-negative breast cancer (TNBC) is an aggressive and highly lethal disease, which warrants the critical need to identify new therapeutic targets. We show that Zinc Fingers and Homeoboxes 2 (ZHX2) is amplified or overexpressed in TNBC cell lines and patients. Functionally, depletion of ZHX2 inhibited TNBC cell growth and invasion in vitro, orthotopic tumor growth, and spontaneous lung metastasis in vivo. Mechanistically, ZHX2 bound with hypoxia-inducible factor (HIF) family members and positively regulated HIF1α activity in TNBC. Integrated ChIP-seq and gene expression profiling demonstrated that ZHX2 co-occupied with HIF1α on transcriptionally active promoters marked by H3K4me3 and H3K27ac, thereby promoting gene expression. Among the identified ZHX2 and HIF1α coregulated genes, overexpression of AP2B1, COX20, KDM3A, or PTGES3L could partially rescue TNBC cell growth defect by ZHX2 depletion, suggested that these downstream targets contribute to the oncogenic role of ZHX2 in an accumulative fashion. Furthermore, multiple residues (R491, R581, and R674) on ZHX2 are important in regulating its phenotype, which correspond with their roles on controlling ZHX2 transcriptional activity in TNBC cells. These studies establish that ZHX2 activates oncogenic HIF1α signaling, therefore serving as a potential therapeutic target for TNBC.

Triple-negative breast cancer (TNBC) is an aggressive and highly lethal disease, which warrants the critical need to identify new therapeutic targets. We show that Zinc Fingers and Homeoboxes 2 (ZHX2) is amplified or overexpressed in TNBC cell lines and patients. Functionally, depletion of ZHX2 inhibited TNBC cell growth and invasion in vitro, orthotopic tumor growth, and spontaneous lung metastasis in vivo. Mechanistically, ZHX2 bound with hypoxia-inducible factor (HIF) family members and positively regulated HIF1α activity in TNBC. Integrated ChIP-seq and gene expression profiling demonstrated that ZHX2 co-occupied with HIF1α on transcriptionally active promoters marked by H3K4me3 and H3K27ac, thereby promoting gene expression. Among the identified ZHX2 and HIF1α coregulated genes, overexpression of AP2B1, COX20, KDM3A, or PTGES3L could partially rescue TNBC cell growth defect by ZHX2 depletion, suggested that these downstream targets contribute to the oncogenic role of ZHX2 in an accumulative fashion. Furthermore, multiple residues (R491, R581, and R674) on ZHX2 are important in regulating its phenotype, which correspond with their roles on controlling ZHX2 transcriptional activity in TNBC cells. These studies establish that ZHX2 activates oncogenic HIF1α signaling, therefore serving as a potential therapeutic target for TNBC.

Clear cell renal cell carcinoma (ccRCC) is characterized by the loss of tumor suppressor Von Hippel Lindau (VHL) function. VHL is the component of an E3 ligase complex that promotes the ubiquitination and degradation of hypoxia inducible factor α (HIF-α) (including HIF1α and HIF2α) and Zinc Fingers And Homeoboxes 2 (ZHX2). Our recent research showed that ZHX2 contributed to ccRCC tumorigenesis in a HIF-independent manner. However, it is still unknown whether ZHX2 could be modified through deubiquitination even in the absence of pVHL. Here, we performed a deubiquitinase (DUB) complementary DNA (cDNA) library binding screen and identified USP13 as a DUB that bound ZHX2 and promoted ZHX2 deubiquitination. As a result, USP13 promoted ZHX2 protein stability in an enzymatically dependent manner, and depletion of USP13 led to ZHX2 down-regulation in ccRCC. Functionally, USP13 depletion led to decreased cell proliferation measured by two-dimensional (2D) colony formation and three-dimensional (3D) anchorage-independent growth. Furthermore, USP13 was essential for ccRCC tumor growth invivo, and the effect was partially mediated by its regulation on ZHX2. Our findings support that USP13 may be a key effector in ccRCC tumorigenesis.

BackgroundThyroid cancer is the most common malignant endocrine tumour, and metastasis has become the main reason for treatment failure. However, the underlying molecular mechanism of thyroid cancer metastasis remains poorly understood. We investigated the role of the tumour suppressor zinc fingers and homeoboxes 2 (ZHX2) in the metastasis of thyroid cancer.MethodsTo study the role of ZHX2 in thyroid cancer metastasis, we evaluated the EMT process using cell migration, wound healing and lung metastatic tumour formation in vitro and in vivo models.ResultsZHX2 expression was significantly decreased in thyroid cancer tissues, which correlated with poor prognosis of thyroid cancer patients. ZHX2 knockdown significantly promoted the migration of thyroid cancer cells. Mechanistically, ZHX2 associated with the S100 calcium binding protein A14 (S100A14) promoter to decrease the transcription of S100A14. Moreover, S100A14 was highly expressed in human thyroid cancer samples, and its expression negatively correlated with ZHX2 expression.ConclusionsInhibition of S100A14 attenuated the ZHX2 knockdown-induced enhanced metastasis of thyroid cancer cells both in vitro and in vivo. The evidence presented here suggests that ZHX2 inhibits the progression of thyroid cancer by blocking S100A14-mediated metastasis.

Initiation of hepatocellular carcinoma (HCC) by chronic hepatitis B virus (HBV) infection is a complex process that includes both oncogene activation and tumor suppressor inhibition. The HBV X (HBx) protein has an important and complex role in processes leading to HCC. We previously identified the mammalian Zinc fingers and homeoboxes 2 (ZHX2) gene as an HCC-associated tumor suppressor gene. In the present study, we investigated whether the oncogenic properties of HBV and, more specifically, HBx, involved ZHX2 silencing. Our data indicates that ZHX2 expression is significantly decreased in tumor tissues from HBV-positive HCC patients and livers from HBV transgenic mice. In vitro and in vivo studies confirmed that HBV-encoded proteins, particularly HBx, inhibits both the expression and tumor suppression properties of ZHX2. Further analyses identified miR-155, a well-known oncomiR in various cancers, as an important link between HBx and ZHX2 inhibition. Increased miR-155 levels were found in HBV-positive tumors, livers of HBV transgenic mice and HBx-overexpressing hepatoma cell lines. MiR-155 overexpression reduced ZHX2 levels via miR-155 seed sites in the ZHX2 3'UTR, whereas blocking miR-155 levels led to increased ZHX2 levels. Taken together, our data indicate that HCC-promoting properties of HBV may include ZHX2 silencing via a miR-155 dependent pathway and suggests a novel therapy for HBV-related HCC.

Given the high mortality associated with Cirrhotic Portal Hypertension (CPH) worldwide, this study investigates the mechanism by which baicalin (BA), known for its beneficial effects on cirrhosis, alleviates CPH. The CPH model was established in Sprague-Dawley (SD) rats, followed by 4-week oral administration of 30 and 60 mg/kg/day BA. SD rats were randomly assigned to four groups (n=6/group): Con, Model, BA-30, and BA-60. Portal vein smooth muscle cells (PVSMCs, extracted from SD rats, n=6) were incubated with 5, 10 and 20 μmol/L BA. The levels of liver function indicators and von Willebrand factor (vWF) were determined by biochemical and immunohistochemical analyses, respectively. The portal pressure (PP) was examined. The liver fibrosis was detected by Sirius red staining. The levels of fibrosis-, angiogenesis- and proliferation- related indicators, zinc fingers and homeoboxes 2 (ZHX2), and matrix metallopeptidase 14 (MMP14) were quantified by Western blot. The levels of and interaction between ZHX2 and MMP14 were separately measured by quantitative real-time polymerase chain reaction (qRTPCR) and luciferase reporter assay. The proliferation and migration of PVSMCs were assessed by EdU staining and scratch test, respectively. BA up-regulated ZHX2 and down-regulated MMP14 (P<0.001). BA concentrationdependently suppressed liver fibrosis, PP, and angiogenesis in the liver tissue, as well as PVSMC proliferation and migration, while enhancing liver function (P<0.05). Further, according to the GRNdb database and luciferase reporter assay, ZHX2 is bound with the promoter of MMP14. ZHX2 could suppress the MMP14 level (P<0.001). ZHX2 silencing reversed the effects of BA treatment on the proliferation and migration of PVSMCs, whereas MMP14 silencing could further offset the role of ZHX2 silencing in the BA-treated PVSMCs (P<0.05). BA up-regulates ZHX2 to reduce the level of MMP14 and alleviate CPH. Understanding the mechanisms of BA in CPH may provide a foundation for novel interventions to attenuate CPH.

Zinc-fingers and homeoboxes protein 1 (ZHX1) belongs to the ZF (zinc-fingers) class of homeodomain transcription factors, and its function remains largely unknown. ZHX1 has been previously found to interact with the activation domain of the nuclear factor Y subunit A (NFYA) and to have a transcriptional repression activity. Here, we report that the SUMO-E2 conjugating enzyme Ubc9 was identified to interact with ZHX1 by an interaction screen using a yeast two-hybrid system. This interaction was confirmed by co-immunoprecipitation and co-localization assays. Further study showed that ZHX1 is SUMOylated by Ubc9 with SUMO1 at the sites K159, K454, and K626. Furthermore, we demonstrated that the SUMOylation of ZHX1 regulated the stability, ubiquitination and transcriptional activity of ZHX1.

Central nervous system hemangioblastoma (CNS-HB) is the most common manifestation of von Hippel-Lindau disease (VHL). The main axis of the CNS-HB pathway is the VHL-HIF signaling pathway. Recently, we proposed an alternative VHL-JAK-STAT pathway in CNS-HB. In contrast, the VHL substrate transcription factor zinc fingers and homeoboxes 2 (ZHX2) have been identified as the oncogenic drivers in VHL-deficient clear cell renal cell carcinoma (RCC). However, ZHX2 expression in CNS-HB has not been previously reported. Furthermore, the VHL-ZXH2-NF-κB signaling pathway in CNS-HB remains unresolved. In this study, we aimed to investigate ZHX2 expression and VHL gene alteration in CNS-HB and propose the role of ZHX2 in CNS-HB. Using the MACS method, Scl+ hemangioblastoma-like cells were isolated from multipotent nestin-expressing stem cells. The ubiquitination of ZHX2 in these cells and the immunoprecipitation between ZHX2 and VHL were investigated. In addition, the VHL genes of patients with hemangioblastoma were analyzed. ZHX2 expression in CNS-HB tissues was examined by immunohistochemistry and western blotting. In addition, VHL gene mutations in CNS-HB were analyzed by sequencing. The association between ZHX2 expression and VHL gene mutation was analyzed. ZHX2 was ubiquitinated in Scl+hemangioblastoma-like cells after the transfer of the VHL expression vector into these cells. ZHX2 expression in these cells was well detected before transfer but disappeared after the transfer. ZHX2 expression was detected in 18 of the 21 CNS-HB tissues by immunoblotting and/or immunohistochemistry. Sporadic CNS-HB showed weak expression, whereas VHL-related CNS-HB showed moderate or strong expression. In particular, CNS-HB with severe VHL gene mutations, including large deletions, showed strong or moderate ZHX2 expression. The association between VHL gene mutation and ZHX2 expression revealed a significant correlation between VHL gene alteration severity and the level of immunoblotting (P < 0.05). In conclusion, the severity of VHL gene alteration correlates with the level of ZHX2 expression. ZHX2 is predominantly expressed in CNS-HB, especially in VHL-related cases with severe VHL gene alterations, suggesting a potential role in tumorigenesis and proliferation of CNS-HB.

Introduction: Renal cell carcinoma (RCC) is a common type of kidney cancer with limited treatment options and a high mortality rate. Therefore, it is essential to understand the role and mechanism of key genes in RCC development and progression. This study aimed to analyze the role of zinc fingers and homeoboxes 2 (ZHX2) in RCC and the underlying mechanism. Methods: RNA expression was analyzed by quantitative real-time polymerase chain reaction, while protein expression was analyzed by Western blotting assay and immunohistochemistry assay. Cell viability was evaluated using CCK-8 assay, and cell proliferation was assessed by EdU assay. The rate of cell apoptosis was quantified by flow cytometry. Transwell assays were conducted to analyze cell migration and invasion. The sphere formation assay was performed to assess the formation of microspheres. Additionally, m6A RNA immunoprecipitation assay and RNA immunoprecipitation assay were utilized to investigate the relationship between ZHX2 and two proteins, methyltransferase like 3 (METTL3) and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1). The stability of ZHX2 mRNA was analyzed through the Actinomycin D assay. Furthermore, a xenograft mouse model assay was conducted to analyze the effect of ZHX2 overexpression and METTL3 silencing on RCC cell tumor properties in vivo. Results: ZHX2 expression was upregulated in both RCC tissues and cells when compared with healthy renal tissues and human renal cortex proximal convoluted tubule epithelial cells. Depletion of ZHX2 inhibited RCC cell proliferation, migration, invasion, and spheroid-forming capacity but promoted cell apoptosis. Moreover, it was found that METTL3-mediated m6A methylation of ZHX2 and IGF2BP1 also stabilized ZHX2 through m6A methylation modification. Furthermore, ZHX2 overexpression showed a potential for attenuating the effects induced by METTL3 silencing and counteracted the inhibitory effect of METTL3 depletion on tumor formation in vivo. Conclusion: METTL3 and IGF2BP1-mediated m6A modification of ZHX2 promoted RCC progression. The finding suggests that ZHX2 may serve as a potential therapeutic target in RCC, providing valuable insights for future clinical interventions.

ObjectiveMetabolic dysfunction-associated steatotic liver disease (MASLD) is a common complication of type 2 diabetes mellitus (DM). The transcription factor zinc fingers and homeoboxes 2 (ZHX2) has been implicated in the pathogenesis of chronic liver diseases, yet its precise role and underlying mechanism in DM-induced hepatic injury remain poorly elucidated.MethodsTo investigate this, we used a high-fat diet (HFD) and streptozotocin (STZ) administration to create a DM model in mice, while high glucose (HG) exposure was used to simulate DM in vitro. Through various experiments such as luciferase reporter assay, chromatin immunoprecipitation, RNA immunoprecipitation, and rescue experiments, we aimed to uncover the mechanisms involving ZHX2.ResultsOur findings revealed that ZHX2 was lower and YTHDF2 was higher in the livers of DM mice and HG-induced Huh7 cells. ZHX2 overexpression rescued DM-induced liver injury. ZHX2 overexpression also reversed DM-induced hepatic ferroptosis in vivo and in vitro. Mechanistically, YTHDF2 recognized m6A-modified ZHX2 mRNA and promoted its degradation. In turn, ZHX2 inhibited the transcription of YTHDF2 by binding to its promoter region. Knockdown of ZHX2 led to increased ferroptosis in Huh7 cells through activating YTHDF2-induced GPX4 and SLC7A11 degradation.ConclusionThese findings highlight the involvement of the ZHX2-YTHDF2-ferroptosis pathway in DM-induced liver injury and suggest that targeting this pathway may hold therapeutic potential for improving such injuries.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. Lipogenesis has been considered as a critical player in HCC initiation and progression. However, the underlying mechanism is still not fully understood. Here, we identified zinc fingers and homeoboxes 2 (ZHX2), an HCC-associated tumor suppressor, as an important repressor of de novo lipogenesis. Ectopic expression of ZHX2 significantly inhibited de novo lipogenesis in HCC cells and decreased expression of FASN, ACL, ACC1, and SCD1. In accordance with this, ZHX2 was negatively associated with SREBP1c, the master regulator of de novo lipogenesis, in HCC cell lines and human specimens. Results from silencing and overexpression demonstrated that ZHX2 inhibited de novo lipogenesis and consequent HCC progression via repression of SREBP1c. Furthermore, treatment with the SREBP1c inhibitor fatostatin dampened the spontaneous formation of tumors in liver-specific Zhx2 knockout mice. Mechanistically, ZHX2 increased expression of miR-24-3p transcriptionally, which targeted SREBP1c and led to its degradation. In conclusion, our data suggest a novel mechanism through which ZHX2 suppresses HCC progression, which may provide a new strategy for the treatment of HCC. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

N-terminal methylation (Nα-methylation) by the methyltransferase NRMT1 is an important post-translational modification that regulates protein–DNA interactions. Accordingly, its loss impairs functions that are reliant on such interactions, including DNA repair and transcriptional regulation. The global loss of Nα-methylation results in severe developmental and premature aging phenotypes, but given over 300 predicted substrates, it is hard to discern which physiological substrates contribute to each phenotype. One of the most striking phenotypes in NRMT1 knockout (Nrmt1−/− ) mice is early liver degeneration. To identify the disrupted signaling pathways leading to this phenotype and the NRMT1 substrates involved, we performed RNA-sequencing analysis of control and Nrmt1−/− adult mouse livers. We found both a significant upregulation of transcripts in the cytochrome P450 (CYP) family and downregulation of transcripts in the major urinary protein (MUP) family. Interestingly, transcription of both families is inversely regulated by the transcription factor zinc fingers and homeoboxes 2 (ZHX2). ZHX2 contains a non-canonical NRMT1 consensus sequence, indicating that its function could be directly regulated by Nα-methylation. We confirmed misregulation of CYP and MUP mRNA and protein levels in Nrmt1−/− livers and verified NRMT1 can methylate ZHX2 in vitro. In addition, we used a mutant of ZHX2 that cannot be methylated to directly demonstrate Nα-methylation promotes ZHX2 transcription factor activity and target promoter occupancy. Finally, we show Nrmt1−/− mice also exhibit early postnatal de-repression of ZHX2 targets involved in fetal liver development. Taken together, these data implicate ZHX2 misregulation as a driving force behind the liver phenotype seen in Nrmt1−/− mice.