BACKGROUND: Neuroendocrine prostate cancer (NEPC) is a lethal subset of prostate cancer which is characterized by neuroendocrine differentiation and loss of androgen receptor (AR) signaling. Growing evidence reveals that cell lineage plasticity is crucial in the failure of NEPC therapies. Although studies suggest the involvement of the neural transcription factor PAX6 in drug resistance, its specific role in NEPC remains unclear.
METHODS: The expression of PAX6 in NEPC was identified via bioinformatics and immunohistochemistry. CCK8 assay, colony formation assay, tumorsphere formation assay and apoptosis assay were used to illustrate the key role of PAX6 in the progression of in vitro. ChIP and Dual-luciferase reporter assays were conducted to confirm the binding sequences of AR in the promoter region of PAX6, as well as the binding sequences of PAX6 in the promoter regions of STAT5A and MET. For in vivo validation, the xenograft model representing NEPC subtype underwent pathological analysis to verify the significant role of PAX6 in disease progression. Complementary diagnoses were established through public clinical datasets and transcriptome sequencing of specific cell lines. ATAC-seq was used to detect the chromatin accessibility of specific cell lines.
RESULTS: PAX6 expression was significantly elevated in NEPC and negatively regulated by AR signaling. Activation of PAX6 in non-NEPC cells led to NE trans-differentiation, while knock-down of PAX6 in NEPC cells inhibited the development and progression of NEPC. Importantly, loss of AR resulted in an enhanced expression of PAX6, which reprogramed the lineage plasticity of prostate cancer cells to develop NE phenotypes through the MET/STAT5A signaling pathway. Through ATAC-seq, we found that a high expression level of PAX6 elicited enhanced chromatin accessibility, mainly through attenuation of H4K20me3, which typically causes chromatin silence in cancer cells.
CONCLUSIONS: This study reveals a novel neural transcription factor PAX6 could drive NEPC progression and suggest that it might serve as a potential therapeutic target for the management of NEPC.

OBJECTIVE: To explore the potential role of signal transducer and activator of transcription 5A (STAT5A) in the metastasis of breast cancer, and its mechanism of regulation underlying.
RESULTS: TCGA datasets were used to evaluate the expression of STAT5A in normal and different cancerous tissues through TIMER2.0, indicating that STAT5A level was decreased in breast cancer tissues compared with normal ones. Gene Set Enrichment Analysis predicted that STAT5A was associated with the activation of immune cells and cell cycle process. We further demonstrated that the infiltration of immune cells was positively associated with STAT5A level. Influorescence staining revealed the expression and distribution of F-actin was regulated by STAT5A, while colony formation assay, wound healing and transwell assays predicted the inhibitory role of STAT5A in the colony formation, migratory and invasive abilities in breast cancer cells. In addition, overexpression of the Notch3 intracellular domain (N3ICD), the active form of Notch3, resulted in the increased expression of STAT5A. Conversely, silencing of Notch3 expression by siNotch3 decreased STAT5A expression, supporting that STAT5A expression is positively associated with Notch3 in human breast cancer cell lines and breast cancer tissues. Mechanistically, chromatin immunoprecipitation showed that Notch3 was directly bound to the STAT5A promoter and induced the expression of STAT5A. Moreover, overexpressing STAT5A partially reversed the enhanced mobility of breast cancer cells following Notch3 silencing. Low expression of Notch3 and STAT5A predicted poorer prognosis of patients with breast cancer.
CONCLUSIONS: The present study demonstrates that Notch3 inhibits metastasis in breast cancer through inducing transcriptionally STAT5A, which was associated with tumor-infiltrating immune cells, providing a novel strategy to treat breast cancer.

CNVs, which are a type of structural variation, make a substantial impact on diverse characteristics in multiple species. Q-PCR and data association analysis were used for STAT5A gene copy in this study. This study aimed to investigate the copy number variation (CNV) of the STAT5A gene in seven Chinese cattle breeds, namely Qinchuan cattle, Xianan cattle, Yunling cattle, Ji\'an cattle, Jiaxian Red cattle, Qaidam cattle, and Guyuan yellow cattle. Blood samples were collected for CNV typing, and the correlation between CNV type and growth traits was analyzed using SPSS 23.0 software and ANOVA. The findings revealed variations in the distribution of different copy number types among the different cattle breeds. Furthermore, association analysis demonstrated a positive impact of CNV in the STAT5A gene on cattle growth: in the JX, individuals with duplication types exhibited superior performance in terms of rump length (P < 0.05). Conversely, normal GY cattle demonstrated better body height and abdomen circumference (P < 0.05), while QD cattle exhibited a significant correlation between weight and body length with normal individuals (P < 0.05). Moreover, QC bovine duplication individuals outperformed other types, with copy number variation significantly associated with chest depth, chest width, and body length (P < 0.05). The results validate the correlation between copy number variation (CNV) of the STAT5A gene and growth characteristics in five different cattle breeds, providing a reliable benchmark for the purpose of cattle breeding.

Inhibition of STAT5 was recently reported to reduce murine atherosclerosis. However, the role of STAT5 isoforms, and more in particular STAT5A in macrophages in the context of human atherosclerosis remains unknown.
Here, we demonstrate reciprocal expression regulation of STAT5A and STAT5B in human atherosclerotic lesions. The former was highly upregulated in ruptured over stable plaque and correlated with macrophage presence, a finding that was corroborated by the high chromosomal accessibility of STAT5A but not B gene in plaque macrophages. Phosphorylated STAT5 correlated with macrophages confirming its activation status. As macrophage STAT5 is activated by GM-CSF, we studied the effects of its silencing in GM-CSF differentiated human macrophages. STAT5A knockdown blunted the immune response, phagocytosis, cholesterol metabolism, and augmented apoptosis terms on transcriptional levels. These changes could partially be confirmed at functional level, with significant increases in apoptosis and decreases in lipid uptake and IL-6, IL-8, and TNFa cytokine secretion after STAT5A knockdown. Finally, inhibition of general and isoform A specific STAT5 significantly reduced the secretion of TNFa, IL-8 and IL-10 in ex vivo tissue slices of advanced human atherosclerotic plaques.
In summary, we identify STAT5A as an important determinant of macrophage functions and inflammation in the context of atherosclerosis and show its promise as therapeutic target in human atherosclerotic plaque inflammation.

Fluorescence polarization (FP) assays can be used to identify small-molecule inhibitors that bind to SH2 domain-containing proteins. We have developed FP assays by which to identify inhibitors of the SH2 domains of the two closely-related transcription factors STAT5a and STAT5b. Point mutation of selected amino acids in the putative binding site of the protein is a valuable tool by which to gain insight into the molecular mechanism of binding. In this chapter, we describe the cloning and application of point mutant proteins in order to transfer the binding preference of selected SH2 domain-binding STAT5b inhibitors to STAT5a, with results that highlight the importance of considering a role for residues outside the SH2 domain in contributing to the binding interactions of SH2 domain inhibitors.

OBJECTIVE: The Janus kinase/signal transducer and transporter activator (JAK/STAT) signaling pathway plays crucial roles in lipid metabolism, glucose metabolism and cell senescence, suggesting that they are potential candidate genes affecting growth traits in animals. The present study aimed to evaluate the association between InDels in the JAK/STAT pathway and growth traits of four Chinese sheep breeds, including Tong sheep, Hu sheep, Small-tailed Han sheep and Lanzhou fat-tailed sheep.
RESULTS: Seventy-six indel loci of 11 genes in JAK/STAT were detected, and three genotypes were selected at four loci by PCR amplification, electrophoresis and sequencing, including one locus in STAT3, one locus in STAT5A, and two loci in JAK1. The Correlation analysis indicated that there was no significant correlation between STAT3 and growth traits in four sheep breeds (P > 0.05); STAT5A was significantly associated with body height, rump width and tube circumference in Hu sheep and body length in Tong sheep (P < 0.05); JAK1 was significantly correlated with body height, body oblique length, cross height and tube circumference in Hu sheep (P < 0.05) and body oblique length, cross height and tube circumference in small-tailed Han sheep (P < 0.05).
CONCLUSIONS: Overall, our results indicated a potential association between the growth traits of sheep and the InDels of JAK1 and STAT5A.

OBJECTIVE: Multiple transcription factors (TFs) have previously been shown to control hypertrophic chondrocyte-specific mouse type X collagen gene (Col10a1) expression via interaction with Col10a1 promoters. This study aims to investigate the role and mechanism of the potential binding factor signal transduction and transcription activator 5a (Stat5a) of Col10a1 cis-enhancer, in controlling Col10a1 gene expression and chondrocyte hypertrophic differentiation.
METHODS: The potential Col10a1 regulator was predicted by the transcription factor affinity prediction (TRAP) analysis of the 150-bp Col10a1 cis enhancer. Stat5a was screened and verified by qRT-PCR, western blot and IHC analyses. Transfection of Stat5a siRNA or expression plasmid into MCT and ATDC5 cells was performed to either knockdown or over-express Stat5a and to investigate the influence of Stat5a on Col10a1 gene expression during the chondrocyte hypertrophy. Dual-luciferase reporter assay was performed to explore the mechanism of Stat5a affecting Col10a1 transcription. Alcian blue, alkaline phosphatase, and alizarin red staining, as well as qRT-PCR analyses of related marker genes were performed to investigate the effect and possible mechanism of Stat5a on chondrocyte differentiation.
RESULTS: The potential binding factor of Col10a1 cis-enhancer Stat5a and Col10a1 were both highly expressed and positively correlated within hypertrophic chondrocytes in vitro and in situ. Knockdown of Stat5a reduced Col10a1 expression, while overexpression of Stat5a enhanced Col10a1 expression in hypertrophic chondrocytes, suggesting Stat5a as a positive Col10a1 regulator. Mechanistically, Stat5a was shown to potentiate the reporter activity mediated by Col10a1 promoter/enhancer. In addition, Stat5a increased the intensity of alkaline phosphatase staining of ATDC5 cells and the expression of relevant hypertrophic marker genes including Runx2, which was consistent with the expression of Stat5a and Col10a1.
CONCLUSIONS: Our results support that Stat5a promoted Col10a1 expression and chondrocyte hypertrophic differentiation, possibly via interaction with the 150-bp Col10a1 cis-enhancer.

Studies examining the role of signal transducer and activator of transcription 5 (STAT5) in various cancers have produced controversial results. To address this controversy, we examined the prognostic role of STAT5a in cancer patients across multiple cancers. Transcription levels of STAT5a between tumors and normal tissues, obtained from public databases, were analyzed for statistical differences using Cox regression analysis with the outcome as overall survival and covariate of interest as high STAT5a expression. Meta-analysis was then conducted to summarize the hazard ratio estimate from the Cox regression analyses. We found that STAT5a was significantly under-expressed in breast, lung, and ovarian cancers, while STAT5a was significantly overexpressed in lymphoid neoplasm diffuse large B-cell lymphoma, glioblastoma, and glioma. High STAT5a expression was significantly associated with favorable survival in bladder cancer (lnHR = -0.8689 [-1.4087, -0.3292], P-value = 0.0016), breast cancer (lnHR = -0.7805 [-1.1394, -0.4215], P-value < 0.0001) and lung cancer (lnHR = -0.3255 [-0.6427, -0.0083], P-value = 0.0443). After adjusting for clinicopathological factors, high STAT5a expression remained significantly associated with favorable survival in breast cancer (lnHR = -0.6091 [-1.0810, -0.1372], P-value = 0.0114). These results suggest that higher STAT5a expression is associated with favorable overall survival in breast cancer, and therefore might have protective effects, and that STAT5a expression could be a potential prognostic biomarker, especially in breast cancer. However, the prognostic role of STAT5a is dependent on cancer type.

Lipopolysaccharide (LPS) has previously been implicated in insulin resistance by generating an innate immune response and activating inflammatory cascades. Many studies have discovered a relationship between high levels of serum LPS and the advancement of diabetic microvascular problems, indicating that LPS may play a role in the control of critical signaling pathways connected to insulin resistance. The current study focused on signaling pathways linked to insulin resistance and explored probable mechanisms of LPS-induced insulin resistance in a murine model. It next looked at the effects of burdock, bee pollen, and -lipoic acid on LPS-induced inflammation and autoimmune defects in rats. LPS intoxication was induced via ip injection for one week in a dose of 10 mg/kg followed by α-lipoic acid, Burdock and bee pollen in an oral treatment for one month. Following that, biochemical and molecular studies were performed. The RNA expression of the regulating genes STAT5A and PTEN was measured. In addition, ATF-4 and CHOP as autophagy biomarkers were also subjected to mRNA quantification. The results demonstrated a considerable improvement in the -lipoic acid, Burdock, and bee pollen treated groups via modifying oxidative stress indicators as well as molecular ones. Furthermore, glucose concentration in serum and α-amylase were also improved upon treatment with the superiority of α-lipoic acid for modulating all estimated parameters. In conclusion: the results declared in the current study suggested that α-lipoic acid could regulate insulin resistance signaling pathways induced by LPS intoxication.

Definitive diagnosis to sudden cardiac death (SCD) is often challenging since the postmortem examination on SCD victims could hardly demonstrate an adequate cause of death. It is therefore important to uncover the inherited risk component to SCD. Signal transducer and activators of transcription 5 A (STAT5A) is a member of the STAT family and a transcription factor that is activated by many cell ligands and associated with various cardiovascular processes. In this study, we performed a systematic variant screening on the STAT5A to filter potential functional genetic variations. Based on the screening results, an insertion/deletion polymorphism (rs3833144) in 3\'UTR of STAT5A was selected as the candidate variant. A total of 159 SCD cases and 668 SCD matched healthy controls was enrolled to perform a case-control study and evaluate the association between rs3833144 and SCD susceptibility in Chinese populations. Logistic regression analysis showed that the deletion allele of rs3833144 had significantly increased the SCD risk (odds ratio (OR) = 1.54; 95% confidence interval (CI) = 1.18-2.01; P = 0.000955). Further genotype-expression eQTL analysis showed that samples with deletion allele appeared to lower expression of STAT5A, and in silico prediction suggested the local 3 D structure changes of STAT5A mRNA caused by the variant. On the other hand, the bioinformatic analysis presented that promoters of RARA and PTGES3L-AARSD1 could interact with rs3833144, and eQTL analysis showed the higher expression of both genes in samples with deletion allele. Dual-luciferase activity assays also suggested the significant regulatory role of rs3833144 in gene transcription. Our current data thus suggested a possible involvement of rs3833144 to SCD predisposition in Chinese populations and rs3833144 with potential function roles may become a candidate marker for SCD diagnosis and prevention.