Hematopoietic-substrate-1 associated protein X-1 (HAX-1) regulates liver cancer cells growth, metastasis, and angiogenesis through Akt

NOD1 cooperates with HAX-1 to promote cell migration in a RIPK2- and NF-ĸB-independent manner

The human Nod-like receptor protein NOD1 is a well-described pattern-recognition receptor (PRR) with diverse functions. NOD1 associates with F-actin and its protein levels are upregulated in metastatic cancer cells. A hallmark of cancer cells is their ability to migrate, which involves actin remodelling. Using chemotaxis and wound healing assays, we show that NOD1 expression correlated with the migration rate and chemotactic index in the cervical carcinoma cell line HeLa. The effect of NOD1 in cell migration was independent of the downstream kinase RIPK2 and NF-ĸB activity. Additionally, NOD1 negatively regulated the phosphorylation status of cofilin, which inhibits actin turnover. Co-immunoprecipitation assays identified HCLS1-associated protein X-1 (HAX-1) as a previously unknown interaction partner of NOD1. Silencing of HAX-1 expression reduced the migration behaviour to similar levels as NOD1 knockdown, and simultaneous knockdown of NOD1 and HAX-1 showed no additive effect, suggesting that both proteins act in the same pathway. In conclusion, our data revealed an important role of the PRR NOD1 in regulating cell migration as well as chemotaxis in human cervical cancer cells and identified HAX-1 as a protein that interacts with NOD1 and is involved in this signalling pathway.

The Landscape of Liver Chromatin Accessibility and Conserved Non-coding Elements in Larimichthys crocea, Nibea albiflora, and Lateolabrax maculatus

Large yellow croaker (Larimichthys crocea), yellow drum (Nibea albiflora), and Chinese seabass (Lateolabrax maculatus) are important economic marine fishes in China. The conserved non-coding elements (CNEs) in the liver tissues of the three kinds of fish are directly or indirectly involved in the regulation of gene expression and affect liver functions. However, the fishes' CNEs and even chromatin accessibility landscape have not been effectively investigated. Hence, this study established the landscapes of the fishes' genome-wide chromatin accessibility and CNEs by detecting regions of the open chromatin in their livers using an assay for transposase-accessible chromatin by high-throughput sequencing (ATAC-seq) and comparative genomics approach. The results showed that Smad1, Sp1, and Foxl1 transcription factor binding motifs were considerably enriched in the chromatin accessibility landscape in the liver of the three species, and the three transcription factors (TFs) had a wide range of common targets. The hypothetical gene set was targeted by one, two, or all three TFs, which was much higher than would be expected for an accidental outcome. The gene sets near the CNEs were mainly enriched through processes such as a macromolecule metabolic process and ribonucleoprotein complex biogenesis. The active CNEs were found in the promoter regions of genes such as ap1g1, hax1, and ndufs2. And 5 CNEs were predicted to be highly conserved active enhancers. These results demonstrated that Smad1, Sp1, and Foxl1 might be related to the liver function in the three fishes. In addition, we found a series of ATAC-seq-labeled CNEs located in the gene promoter regions, and highly conserved H3k27ac + -labeled CNEs located in the liver function genes. The highly conserved nature of these regulatory elements suggests that they play important roles in the liver in fish. This study mined the landscape of chromatin accessibility and CNEs of three important economic fishes to fill the knowledge gaps in this field. Moreover, the work provides useful data for the industrial application and theoretical research of these three fish species.

Anti-apoptotic HAX-1 suppresses cell apoptosis by promoting c-Abl kinase-involved ROS clearance

The anti-apoptotic protein HAX-1 has been proposed to modulate mitochondrial membrane potential, calcium signaling and actin remodeling. HAX-1 mutation or deficiency results in severe congenital neutropenia (SCN), loss of lymphocytes and neurological impairments by largely unknown mechanisms. Here, we demonstrate that the activation of c-Abl kinase in response to oxidative or genotoxic stress is dependent on HAX-1 association. Cellular reactive oxygen species (ROS) accumulation is inhibited by HAX-1-dependent c-Abl activation, which greatly contributes to the antiapoptotic role of HAX-1 in stress. HAX-1 (Q190X), a loss-of-function mutant responsible for SCN, fails to bind with and activate c-Abl, leading to dysregulated cellular ROS levels, damaged mitochondrial membrane potential and eventually apoptosis. The extensive apoptosis of lymphocytes and neurons in Hax-1-deficient mice could also be remarkably suppressed by c-Abl activation. These findings underline the important roles of ROS clearance in HAX-1-mediated anti-apoptosis by c-Abl kinase activation, providing new insight into the pathology and treatment of HAX-1-related hereditary disease or tumorigenesis.

DRAM1 plays a tumor suppressor role in clear cell renal cell carcinoma through modulating Akt signaling

BACKGROUND

Clear cell renal carcinoma (ccRCC) is one of the most common malignant tumors worldwide. DNA damage-regulated autophagy modulator1 (DRAM1) plays an important roles in apoptosis and tumor progression. However, the role of DRAM1 in ccRCC is still unknown. In our study, we aimed to investigate the effect of DRAM1 in the progression of ccRCC.

METHODS

The expression and prognostic information of DRAM1 in ccRCC were obtained by immunohistochemistry staining and bioinformatics database. Cell proliferation, migration, invasion were detected by CCK-8 assay, wound-healing and transwell assays, and the cell apoptosis was examined by tunel assay and flow cytometry analysis. Western blot was used to detect the expression of DRAM1, Bax, Bcl2, Akt, p53,E-cadherin, N-cadherin of ccRCC cells.

RESULTS

Decreased expression of DRAM1 was found in ccRCC tissues, which predicted a shorter survival rate in ccRCC patient. We confirmed that DRAM1 inhibited the proliferation, migration, invasion and epithelial mesenchymal transformation (EMT), while enhanced the apoptosis of ccRCC cells. In addition, the results of inhibition of Akt signaling were consistent with the above. We further proved that DRAM1 over-expression decreased the phosphorylation of Akt signaling, and overexpression of DRAM1 could reverse oncogenic function induced by the over-activating of Akt in ccRCC cells.

CONCLUSION

overexpression of DRAM1 plays a tumor suppressive role in ccRCC through inactivation of Akt and highlights the potential role of DRAM1 as a prognostic biomarker in ccRCC.

HAX1 maintains the glioma progression in hypoxia through promoting mitochondrial fission

HCLS1‐associated protein X‐1 (HAX1), an anti‐apoptotic molecular, overexpresses in glioma. However, the role of HAX1 in glioma cell surviving in hypoxic environment remains unclear. Western blotting, qRT‐PCR, Transwell assay, TUNEL assay, wounding healing assay, clone formation, tumour xenograft model and immunohistochemical staining were used to investigate the role of HAX1 in glioma. HAX1 regulated by HIF‐1α was increased in glioma cells cultured in hypoxia. Silencing of HAX1 could cause an increased apoptosis of glioma cells cultured in hypoxia. Silencing of HAX1 also decreased the proliferation, migration and invasion of glioma cells cultured in hypoxia. Increased mitochondrial fission could prevent glioma cells from the damage induced by HAX1 knockdown in hypoxia. Furthermore, HAX1 was found to regulate glioma cells through phosphorylated AKT/Drp signal pathway. In conclusion, our study suggested that HAX1 promoted survival of glioma cells in hypoxic environment via AKT/Drp signal pathway. Our study also provided a potential therapeutic target for glioma.

QPCT regulation by CTCF leads to sunitinib resistance in renal cell carcinoma by promoting angiogenesis

Sunitinib is widely used as a first‑line treatment for advanced renal cell carcinoma (RCC). However, a number of patients with RCC who receive sunitinib develop drug resistance; and the biological mechanisms involved in resistance to sunitinib remain unclear. It has previously been suggested that the protein glutaminyl‑peptide cyclotransferase (QPCT) is closely related to sunitinib resistance in RCC. Thus, in the present study, in order to further examine the molecular mechanisms responsible for sunitinib resistance in RCC, sunitinib‑non‑responsive and ‑responsive RCC tissue and plasma samples were collected and additional experiments were performed in order to elucidate the molecular mechanisms responsible for sunitinib resistance in RCC. The upstream and downstream regulatory mechanisms of QPCT were also evaluated. On the whole, the data from the present study suggest that QPCT, CCCTC‑binding factor (CTCF) and phosphatidylinositol‑4,5‑bisphosphate 3‑kinase catalytic subunit alpha (PIK3CA) may be used as targets for predicting, reversing and treating sunitinib‑resistant RCC.

Expression of Integrin β6 and HAX-1 Correlates with Aggressive Features and Poor Prognosis in Esophageal Squamous Cell Carcinoma

Purpose

The development of esophageal squamous cell carcinoma (ESCC) is a complicated process in which cell adhesion and motility, mediated by integrins, are involved through connecting the cytoskeleton to extracellular matrix. Different mechanisms via which integrin β6 participates in cancer invasion and metastasis have been described by numerous studies; however, the expression and clinical significance of integrin β6 in ESCC remain unknown.

Methods

To investigate the differential expression of integrin β6 in ESCC, qPCR and immunohistochemistry assays were performed in 10 paired human samples. A total of 137 ESCC samples were further enrolled to evaluate the expression levels of integrin β6 and its endocytic trafficking regulator HS1-associated protein X-1 (HAX-1), followed by the evaluation of their correlation with clinicopathological parameters. The overall survival was analyzed using the Kaplan–Meier method, with significant variables further evaluated by multivariate Cox regression analyses.

Results

The expression of integrin β6 was markedly increased in ESCC compared with matched adjacent normal tissues. Among the ESCC samples, positive expression of integrin β6 was observed in 41.6% tumors, which was associated with histological differentiation, lymph node metastasis and TNM stage. High expression of HAX-1 was detected in 47.4% tumors, and there was a positive relationship between the expression levels of integrin β6 and HAX-1. Furthermore, the expression of integrin β6 and HAX-1 were independent unfavorable indicators for prognosis. Patients with positive integrin β6 and high HAX-1 expression demonstrated worst outcomes.

Conclusion

The present findings suggested the predictive value of integrin β6 and HAX-1 as independent indicators of poor prognosis for patients with ESCC, both of which may contribute to the tumor proliferation and metastasis, leading to ESCC progression. Therefore, combined targeting of integrin β6 and HAX-1 may provide a potential novel approach for the treatment of ESCC.

CPNE1-mediated neuronal differentiation can be inhibited by HAX1 expression in HiB5 cells

We previously demonstrated that CPNE1 induces neuronal differentiation and identified two binding proteins of CPNE1 (14-3-3γ and Jab1) as potential regulators of CPNE1-mediated neuronal differentiation in hippocampal progenitor cells. To better understand the cellular processes in which CPNE1 participates in neuronal differentiation, we here carried out a yeast two-hybrid screening to find another CPNE1 binding protein. Among the identified proteins, HCLS1-related protein X-1 (HAX1) directly interacts with CPNE1. Immunostaining experiments showed that a fraction of CPNE1 and HAX1 co-localized in the cytosol, particularly in the plasma membrane. In addition, the physical interaction as well as the specific binding regions between CPNE1 and HAX1 were confirmed in vitro and in vivo. Moreover, AKT phosphorylation, Tuj1 (neuronal marker protein) expression, and neurite outgrowth are all reduced in CPNE1/HAX1 overexpressing cells compared to CPNE1 only overexpressing HiB5 cells. Conversely, the HAX1 mutant that does not bind to CPNE1 was unable to inhibit the CPNE1-mediated neuronal differentiation. Together these results indicate that HAX1 is a binding partner of CPNE1 and CPNE1-mediated neuronal differentiation is negatively affected through the binding of HAX1, especially its N-terminal region, with CPNE1.

MicroRNA‑125a‑5p regulates liver cancer cell growth, migration and invasion and EMT by targeting HAX1

To date, the role of hematopoietic‑substrate‑1‑associated protein X‑1 (HAX1) in liver cancer is rarely studied. The present study explored the role of HAX1 in liver cancer. The association between HAX1 expression and survival of patients with liver cancer was analyzed by a log‑rank test. The target genes for HAX1 was predicted by TargetScan and verified by a dual‑luciferase reporter assay. The protein and mRNA expressions of HAX1 in liver cancer and adjacent non‑cancerous tissues were examined by immunohistochemistry and reverse transcription‑quantitative PCR (RT‑qPCR). The transfection efficiency of HAX1, small interfering RNA against HAX1, microRNA (miR)‑125a mimics, miR‑125a inhibitor, miR‑223 mimics and miR‑223 inhibitor in liver cancer cells was determined by RT‑qPCR. The expression of HAX1, p53, VEGF, epithelial‑to‑mesenchymal transition (EMT)‑related markers (E‑cadherin, N‑cadherin and vimentin) in the cancer cells were determined by western blotting and RT‑qPCR. Cell viability, migration, invasion and colony formation rates were determined by Cell Counting Kot‑8, wound healing, Transwell and colony formation assays, respectively. The results showed that high expression of HAX1 in liver cancer was found relate to poor prognosis in patients with liver cancer, and upregulation of HAX1 expression in liver cancer tissues was related to lower overall survival. miR‑125a‑5p directly binds to HAX1. Upregulation of miR‑125a‑5p expression inhibited cell viability, migration, invasion and colony formation of SK‑Hep1 cells and reduced the expression of HAX1, VEGF, N‑cadherin and vimentin, but increased cell apoptosis and the expression of p53 and E‑cadherin. However, the effects miR‑125a‑5p upregulation were partially reversed by SK‑Hep1 cells with HAX1 overexpression. Downregulated miR‑125a‑5p in SNU‑387 cells produced opposite effects, which was partially reversed by HAX silencing. In conclusion, miR‑125a‑5p suppresses liver cancer growth via targeting HAX1 and concurrently modulating the expression of p53 and VEGF and EMT‑related markers.