MAP3K1 regulates female reproductive tract development

Mitogen-activated protein 3 kinase 1 (MAP3K1) has a plethora of cell type-specific functions not yet fully understood. Herein, we describe a role for MAP3K1 in female reproductive tract (FRT) development. MAP3K1 kinase domain-deficient female mice exhibited an imperforate vagina, labor failure and infertility. These defects corresponded with shunted Müllerian ducts (MDs), the embryonic precursors of FRT, that manifested as a contorted caudal vagina and abrogated vaginal-urogenital sinus fusion in neonates. The MAP3K1 kinase domain is required for optimal activation of the Jun-N-terminal kinase (JNK) and cell polarity in the MD epithelium, and for upregulation of WNT signaling in the mesenchyme surrounding the caudal MD. The MAP3K1-deficient epithelial cells and MD epithelium had reduced expression of WNT7B ligands. Correspondingly, conditioned media derived from MAP3K1-competent, but not -deficient, epithelial cells activated a TCF/Lef-luciferase reporter in fibroblasts. These observations indicate that MAP3K1 regulates MD caudal elongation and FRT development, in part through the induction of paracrine factors in the epithelium that trans-activate WNT signaling in the mesenchyme.

MAP3K1 expression is associated with progression and poor prognosis of hormone receptor-positive, HER2-negative early-stage breast cancer

PURPOSE

In this study, we assessed whether the overexpression of MAP3K1 promotes the proliferation, migration, and invasion of breast cancer cells, which affect the prognosis of hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative early stage breast cancer.

METHODS

Two HR-positive, HER2-negative breast cancer cell lines (MCF7 and T-47D) overexpressing MAP3K1 were transfected with two MAP3K1 short hairpin RNA plasmids (shMAP3K1 [#3] and shMAP3K1 [#5]). The proliferation, migration, and invasion of these cells were then examined. We assessed whether shMAP3K1 affects the cell cycle, levels of downstream signaling molecules (ERK, JNK, p38 MAPK, and NF-κB), and sensitivity to chemotherapeutic and hormonal agents. To assess the anti-tumor effect of MAP3K1 knockdown in the breast cancer orthotopic model, MCF7 and T-47D cells treated with or without shMAP3K1 (#3) and shMAP3K1 (#5) were inoculated into the mammary fat pads of mice. In total, 182 patients with HR-positive, HER2-negative T1 and T2 breast cancer and 0-3 nodal metastases were included. Additionally, 73 patients with T1 and T2 breast cancer and negative nodes who received adjuvant endocrine therapy alone were selected as an independent validation cohort.

RESULTS

In both cell lines, shMAP3K1 (#3) and shMAP3K1 (#5) significantly reduced cell growth, migration, and invasion by downregulating MMP-9 and by blocking the G2/M phase of the cell cycle and its regulatory molecule cyclin B1. Moreover, both shMAP3K1 (#3) and shMAP3K1 (#5) downregulated ERK-, JNK-, p38 MAPK-, and NF-κB-dependent gene transcription and enhanced the sensitivity of both cell lines to doxorubicin, docetaxel, and tamoxifen. We observed that both shMAP3K1 (#3) and shMAP3K1 (#5) inhibited tumor growth compared with that in the scrambled group of MCF7 and T-47D cell orthotopic tumors. Patients with MAP3K1 overexpression exhibited significantly poorer 10-year disease-free survival (DFS) (70.4% vs. 88.6%, p = 0.003) and overall survival (OS) (81.9% vs. 96.3%, p = 0.001) than those without MAP3K1 overexpression. Furthermore, phospho-ERK (p < 0.001) and phospho-JNK (p < 0.001) expressions were significantly associated with MAP3K1 expression, and both phospho-ERK and phospho-JNK expressions were significantly correlated with poor 10-year DFS and OS. These biological findings, including a significant association between DFS and OS, and the expressions of MAP3K1, phospho-ERK, and phospho-JNK were further validated in an independent cohort. Multivariate analysis identified MAP3K1 expression as an independent poor prognostic factor for DFS and OS.

CONCLUSION

Our results indicate that the overexpression of MAP3K1 plays a major role in the poor prognosis of HR-positive, HER2-negative early stage breast cancer.

Insights into the regulation of MAP3K1 in hair follicle stem cells by transcriptome analysis

MAP3K1 is a significant member of the MAPK family, and its expressed MEKK1 protein has a wide range of biological activities and is an essential node in the MAPK signaling pathway. A significant number of studies have revealed that MAP3K1 plays a complicated function in the control of cell proliferation, apoptosis, invasion and movement, participates in the regulation of the immune system, and plays an important role in wound healing, tumorigenesis and other processes. In this study, we looked at the involvement of MAP3K1 in the control of hair follicle stem cells (HFSCs). Overexpression of MAP3K1 significantly promoted the proliferation of HFSCs by inhibiting apoptosis and promoting the transition from S phase to G2 phase. The transcriptome identified 189 (MAP3K1_OE) and 414 (MAP3K1_sh) differential genes. The two pathways with the most significant enrichment of differentially expressed genes were the IL-17 signaling pathway and TNF signaling pathway, and the significantly enriched terms in the GO enrichment analysis involved regulation of response of external stimulus, inflammatory and cytokine. Indicate that MAP3K1 can function as a promoting factor in HFSCs through the induction of cell cycle transition from S phase to G2 phase can inhibition apoptosis by mediating crosstalk among several pathways and cytokines.HIGHLIGHTSAbnormal MAP3K1 expression in hair follicle stem cells (HFSCs) can impair HFSC proliferation and apoptosis.MAP3K1 controls hair follicle stem cell proliferation via modulating cell apoptosis and the ratio of cells in S phase/G2 phase.The differential genes shared by MAP3K1_sh and MAP3K1_OE are enriched in GO terms such as inflammation, adipocyte differentiation, acute inflammation, and so on.

Silencing circPalm2 inhibits sepsis-induced acute lung injury by sponging miR-376b-3p and targeting MAP3K1

The apoptosis and inflammation of pulmonary epithelial cells are important pathogenic factors of sepsis-induced acute lung injury (ALI). Upregulation of circPalm2 (circ_0001212) expression levels has been previously detected in the lung tissue of ALI rats. Herein, the biological significance and detailed mechanism of circPalm2 in ALI pathogenesis were investigated. In vivo models of sepsis-induced ALI were established by treating C57BL/6 mice with cecal ligation and puncture (CLP) surgery. Murine pulmonary epithelial cells (MLE-12 cells) were stimulated with lipopolysaccharide (LPS) to establish in vitro septic ALI models. MLE-12 cell viability and apoptosis were evaluated by CCK-8 assay and flow cytometry analysis, respectively. The pathological alterations of the lung tissue were analysed based on hematoxylin-eosin (H&E) staining. Cell apoptosis in the lung tissue samples was examined by TUNEL staining assay. LPS administration suppressed the viability and accelerated the inflammation and apoptotic behaviours of MLE-12 cells. CircPalm2 displayed high expression in LPS-stimulated MLE-12 cells and possessed circular characteristics. The silencing of circPalm2 impeded apoptosis and inflammation in LPS-stimulated MLE-12 cells. Mechanistically, circPalm2 bound with miR-376b-3p, which targeted MAP3K1. In rescue assays, MAP3K1 enhancement reversed the repressive effects of circPalm2 depletion on LPS-triggered inflammatory injury and MLE-12 cell apoptosis. Furthermore, the lung tissue collected from CLP model mice displayed low miR-376b-3p expression and high levels of circPalm2 and MAP3K1. CircPalm2 positively regulated MAP3K1 expression by downregulating miR-376b-3p in murine lung tissues. Importantly, circPalm2 knockdown attenuated CLP-induced inflammation, apoptosis, and pathological alterations in lung tissues collected from mice. Silenced circPalm2 inhibits LPS-induced pulmonary epithelial cell dysfunction and mitigates abnormalities in lung tissues collected from CLP-stimulated mice via the miR-376b-3p/MAP3K1 axis in septic ALI.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43188-022-00169-7.

MAP3K1 rs889312 polymorphism and cancer prognosis: A systematic review and meta-analysis

BACKGROUND

Accumulating studies have evaluated the association between MAP3K1 polymorphisms and cancer prognosis. However, the results of these studies are conflicting. Given the potential impact of MAP3K1 rs889312 SNP on the prognosis of various cancers, this meta-analysis was performed to obtain solid and credible evidence.

METHODS AND MATERIALS

This study was performed according to the PRISMA 2020 statement. A comprehensive article search was conducted to find and select articles from multiple databases, including PubMed, Google Scholar, Web of Science, EMBASE and the Cochrane Library, published up to 15th September 2022. The data analysis was performed with Review Manager v5.2. Pooled HR with its 95% CI and p-value was calculated where HR >1 suggests worse/poor survival and HR <1 suggests better survival of cancer patients.

RESULTS

A total of five articles comprising 24 439 patients were included for both qualitative and quantitative data synthesis. It was found that only the dominant genetic model (AC + CC vs. AA) showed a statistically significant poor overall survival for MAP3K1 rs889312 polymorphism (HR = 1.25, 95% CI = 1.06-1.47, p = .01). In addition, publication bias analysis by the Egger's test and the Begg-Mazumdar test reported no significant bias in the analysis of overall survival (p > .05).

CONCLUSIONS

The present study concludes that MAP3K1 gene rs889312 polymorphism plays a prognostic role in the survival of cancer patients. However, future research is recommended that will analyze more MAP3K SNPs along with rs889312, which may reveal more credible outcomes in terms of cancer prognosis.

Sex-dependent associations between MAP3K1 gene polymorphisms and soy products with the gastric cancer risk in Korea: a case-control study

BACKGROUND/OBJECTIVES

The hormone-dependent effect of MAP3K1 gene polymorphisms may explain sex-specific differences in gastric cancer (GC) risk. Phytoestrogens have been shown to interact with this genetic factor. Here, we investigated the association between MAP3K1 gene polymorphisms and GC risk by sex and whether these associations differ depending on soy products intake.

METHODS

Participants aged 20-79 years were recruited from two hospitals between December 2002 and September 2006. In all, 440 cases and 485 controls were recruited, among, 246 pairs of cases and controls, matched by sex, age (± 5 years), study admission period (± 1 years), and hospital, were included for the analysis.

RESULTS

In dominant model, men with the A allele of rs252902 showed significantly increased GC risk (odd ratio; OR=2.19, 95% confidence interval; CI=1.31-3.64) compared to GG homozygotes. When stratified by intake of soy products, men with the A allele of rs252902 and low intake of soy products showed significantly higher GC risk (OR=3.29, 95% CI=1.55-6.78) than that in GG homozygotes.

CONCLUSIONS

Men with the risk allele of MAP3K1 had a significantly increased GC risk compared to GG homozygotes; this trend was more pronounced in those with low intake of soy products.

Novel mutation of MAP3K1 gene in 46,XY DSD with complete gonadal dysgenesis

OBJECTIVE

Swyer syndrome, or 46, XY complete gonadal dysgenesis, is a disorder of human sexual development which present with female external genitalia, lack of female reproductive organs, and a 46, XY karyotype. Many genes that participate in human sexual development have been implicated in the pathogenesis of 46, XY gonadal dysgenesis.

CASE REPORT

A 18-year-old phenotypically female was presented with primary amenorrhea. Surveillance revealed hypergonadotropic hypogonadism, a normal male 46, XY karyotype and absent of functional gonad, which was confirmed by pathological examination of the streak gonad. Whole exome sequencing showed germline mutations of a novel missense variant, c.570G > C, p.Lys190Asn, in exon 2 of MAP3K1 gene.

CONCLUSION

Given evolutionary conservation of lysine residue at position 190, the amino acid substitution may interfere with interaction between MAP3K1 and RHOA, and contributes to complete gonadal dysgenesis in the context of 46,XY.

miR-375 Induced the Formation and Transgenerational Inheritance of Fatty Liver in Poultry by Targeting MAP3K1

The liver of poultry is the primary site of lipid synthesis. The excessive production of lipids accumulates in liver tissues causing lipid metabolism disorders, which result in fatty liver disease and have a transgenerational effect of acquired phenotypes. However, its specific mechanisms have not yet been fully understood. In this study, the differentially expressed miR-375 as well as its target gene MAP3K1 (mitogen-activated protein kinase kinase kinase 1) were screened out by interaction network analysis of microRNA sequencing results and transcriptome profiling in the fatty liver group of the F0-F3 generation (p < 0.05 or p < 0.01). Furthermore, the results showed that the number of lipid droplets and triglyceride content were significantly decreased after upregulation of miR-375 in primary hepatocyte culture in vitro (p < 0.05 or p < 0.01). The MAP3K1 knockdown group exhibited the opposite trends (p < 0.05 or p < 0.01). P53, Bcl-x, PMP22, and CDKN2C related to cell proliferation were significantly upregulated or downregulated after knocking down MAP3K1 (p < 0.05). This research uniquely revealed that silencing miR-375 inhibits lipid biosynthesis and promotes cell proliferation, which may be due to the partial regulation of the expression level of MAP3K1, thereby further participating in the transgenerational inheritance process of regulating liver lipid metabolism. These results reveal the pathogenesis of fatty liver in noncoding RNA and provide good candidate genes for breeding progress of disease resistance in chickens.

MicroRNA-203a-3p may prevent the development of thyroid papillary carcinoma via repressing MAP3K1 and activating autophagy

Background

Papillary thyroid carcinoma (PTC) grows slowly but has a great risk of metastasis. MicroRNAs are well known as vital tumor‐related gene regulators. In PTC, the role of miR‐203a‐3p and the underlying mechanisms remain not completely understood.

Methods

We conducted CCK8 assay, wound healing assay, transwell experiment and flow cytometry analyses to investigate the function of miRNA‐203a‐3p. The interaction of miRNA‐203a‐3p with its gene MAP3K1 was characterized by quantitative real‐time polymerase chain reaction, western blotting and luciferase assay.

Results

We found that the levels of miRNA‐203a‐3p were statistically decreased in PTC tissues. When mimics were delivered to TPC‐1 and KTC‐1 cells to upregulate miR‐203a‐3p, it was observed that cell proliferation, metastatic abilities and cell cycle process were prevented but cell apoptosis was enhanced. Furthermore, we proved the interaction between MAP3K1 and miR‐203a‐3p. Intriguingly, similar to miR‐203a‐3p mimics, siMAP3K1 showed a tumor‐suppressive effect, and this effect could be reversed when miR‐203a‐3p was simultaneously inhibited. Finally, selected autophagy‐linked proteins such as LC3 Beclin‐1 were detected and found to be increased when miR‐203a‐3p was upregulated or MAP3K1 was inhibited.

Conclusion

Overall, miR‐203a‐3p inhibits the oncogenic characteristics of TPC‐1 and KTC‐1 cells via suppressing MAP3K1 and activating autophagy. Our findings might enrich the understanding and the therapeutic strategies of PTC.

Small-molecule IKKβ activation modulator (IKAM) targets MAP3K1 and inhibits pancreatic tumor growth

Activation of inhibitor of nuclear factor NF-κB kinase subunit-β (IKKβ), characterized by phosphorylation of activation loop serine residues 177 and 181, has been implicated in the early onset of cancer. On the other hand, tissue-specific IKKβ knockout in Kras mutation-driven mouse models stalled the disease in the precancerous stage. In this study, we used cell line models, tumor growth studies, and patient samples to assess the role of IKKβ and its activation in cancer. We also conducted a hit-to-lead optimization study that led to the identification of 39-100 as a selective mitogen-activated protein kinase kinase kinase (MAP3K) 1 inhibitor. We show that IKKβ is not required for growth of Kras mutant pancreatic cancer (PC) cells but is critical for PC tumor growth in mice. We also observed elevated basal levels of activated IKKβ in PC cell lines, PC patient-derived tumors, and liver metastases, implicating it in disease onset and progression. Optimization of an ATP noncompetitive IKKβ inhibitor resulted in the identification of 39-100, an orally bioavailable inhibitor with improved potency and pharmacokinetic properties. The compound 39-100 did not inhibit IKKβ but inhibited the IKKβ kinase MAP3K1 with low-micromolar potency. MAP3K1-mediated IKKβ phosphorylation was inhibited by 39-100, thus we termed it IKKβ activation modulator (IKAM) 1. In PC models, IKAM-1 reduced activated IKKβ levels, inhibited tumor growth, and reduced metastasis. Our findings suggests that MAP3K1-mediated IKKβ activation contributes to KRAS mutation-associated PC growth and IKAM-1 is a viable pretherapeutic lead that targets this pathway.

The MAP3K1/c-JUN signaling axis regulates glioblastoma stem cell invasion and tumor progression

Glioblastoma (GBM) stem cells (GSCs) are responsible for GBM initiation, progression, infiltration, standard therapy resistance, and recurrence. However, the mechanisms underlying GSC invasion remain incompletely understood. Using public single-cell RNA-Seq data, we identified MAP3K1 as a master regulator of infiltrative GSCs through c-JUN signaling regulation. MAP3K1 knockdown significantly decreased GSC invasion capacity, proliferation, and stemness in vitro. Moreover, in an orthotopic xenograft model, knockdown of MAP3K1 prominently suppressed GSC infiltration along the corpus callosum and tumor progression and prolonged mouse survival. Mechanistically, MAP3K1 regulates GSC invasion through phosphorylation of downstream c-JUN at serine 63 and 73, as confirmed using the CPTAC phosphoproteome dataset. Furthermore, the c-JUN inhibitor JNK-IN-8 significantly decreased GSC invasion, proliferation, and stemness. Taken together, our study demonstrates that MAP3K1 regulates GSC invasion and tumor progression via activation of c-JUN signaling and indicates that the MAP3K1/c-JUN signaling axis is a therapeutic target for infiltrative GBM.

Genetic Control of MAP3K1 in Eye Development and Sex Differentiation

The MAP3K1 is responsible for transmitting signals to activate specific MAP2K-MAPK cascades. Following the initial biochemical characterization, genetic mouse models have taken center stage to elucidate how MAP3K1 regulates biological functions. To that end, mice were generated with the ablation of the entire Map3k1 gene, the kinase domain coding sequences, or ubiquitin ligase domain mutations. Analyses of the mutants identify diverse roles that MAP3K1 plays in embryonic survival, maturation of T/B cells, and development of sensory organs, including eye and ear. Specifically in eye development, Map3k1 loss-of-function was found to be autosomal recessive for congenital eye abnormalities, but became autosomal dominant in combination with Jnk and RhoA mutations. Additionally, Map3k1 mutation increased eye defects with an exposure to environmental agents such as dioxin. Data from eye developmental models reveal the nexus role of MAP3K1 in integrating genetic and environmental signals to control developmental activities. Here, we focus the discussions on recent advances in understanding the signaling mechanisms of MAP3K1 in eye development in mice and in sex differentiation from human genomics findings. The research works featured here lead to a deeper understanding of the in vivo signaling network, the mechanisms of gene-environment interactions, and the relevance of this multifaceted protein kinase in disease etiology and pathogenesis.

Extracellular vesicles secreted from mesenchymal stem cells exert anti-apoptotic and anti-inflammatory effects via transmitting microRNA-18b in rats with diabetic retinopathy

Diabetic retinopathy (DR) is a major cause of visual deficits and blindness in the working-age population and inflammatory response is a key event during DR. In this study, we investigated the anti-inflammatory properties of small extracellular vesicles (sEVs) derived from human umbilical cord mesenchymal stem cells (hUCMSCs) in a diabetic rat model and human retinal microvascular endothelial cells. After development of DR in rats subjected to diabetes induction with streptozotocin (STZ), the DR rats were treated with different concentrations of hUCMSC-sEVs. Our results showed that the treatment of the retinas of DR rats with hUCMSC-sEVs not only reduced the level of vascular leakage in the retinas of rats but also decreased the retinal thickness as well as the associated inflammation. Further, our in vitro evidences suggest that hUCMSC-sEVs repress high glucose (HG)-induced cell inflammation and apoptosis. Subsequently, we analyzed the differentially expressed microRNAs (miRNAs) in the hUCMSC-sEVs by microarray and performed in silico studies to predict the target mRNA of miR-18b. Our findings also revealed that the expression of miR-18b was significantly elevated in the retina of diabetic rats after sEV treatment. In addition, miR-18b was found to target mitogen-activated protein kinase kinase kinase 1 (MAP3K1), thereby inhibiting NF-κB p65 phosphorylation to alleviate DR. Overall, this study highlights the potential of hUCMSCs-sEVs as biomaterials for anti-inflammatory and anti-apoptotic effects in DR by transferring miR-18b.

Oestrogen Activates the MAP3K1 Cascade and β-Catenin to Promote Granulosa-like Cell Fate in a Human Testis-Derived Cell Line

Sex determination triggers the differentiation of the bi-potential gonad into either an ovary or testis. In non-mammalian vertebrates, the presence or absence of oestrogen dictates gonad differentiation, while in mammals, this mechanism has been supplanted by the testis-determining gene SRY. Exogenous oestrogen can override this genetic trigger to shift somatic cell fate in the gonad towards ovarian developmental pathways by limiting the bioavailability of the key testis factor SOX9 within somatic cells. Our previous work has implicated the MAPK pathway in mediating the rapid cellular response to oestrogen. We performed proteomic and phosphoproteomic analyses to investigate the precise mechanism through which oestrogen impacts these pathways to activate β-catenin-a factor essential for ovarian development. We show that oestrogen can activate β-catenin within 30 min, concomitant with the cytoplasmic retention of SOX9. This occurs through changes to the MAP3K1 cascade, suggesting this pathway is a mechanism through which oestrogen influences gonad somatic cell fate. We demonstrate that oestrogen can promote the shift from SOX9 pro-testis activity to β-catenin pro-ovary activity through activation of MAP3K1. Our findings define a previously unknown mechanism through which oestrogen can promote a switch in gonad somatic cell fate and provided novel insights into the impacts of exogenous oestrogen exposure on the testis.

Tumor Cell-Derived Exosomal miR-770 Inhibits M2 Macrophage Polarization via Targeting MAP3K1 to Inhibit the Invasion of Non-small Cell Lung Cancer Cells

Background

Non-small cell lung carcinoma (NSCLC) is a type lung cancer with high malignant behaviors. MicroRNAs (miRNAs) are known to be involved in progression of NSCLC. In order to explore potential targets for the treatment of NSCLC, bioinformatics tool was used to analyze differential expressed miRNAs between NSCLC and adjacent normal tissues.

Methods

Bioinformatics tool was used to find potential targets for NSCLC. Cell proliferation was investigated by Ki67 staining. Cell apoptosis was measured by flow cytometry. mRNA and protein expression in NSCLC cells were detected by RT-qPCR and Western-blot, respectively. Transwell assay was performed to test the cell migration and invasion. In order to investigate the function of exosomal miRNA in NSCLC, in vivo model of NSCLC was constructed.

Results

MiR-770 was identified to be downregulated in NSCLC, and miR-770 agomir could significantly inhibit NSCLC cell proliferation through inducing the apoptosis. Additionally, the metastasis of NSCLC cells was decreased by miR-770 agomir. MAP3K1 was identified to be the target mRNA of miR-770. Meanwhile, tumor cell-derived exosomal miR-770 inhibited M2 macrophage polarization via downregulation of MAP3K1, which in turn suppressed NSCLC cell invasion. Besides, tumor cell-derived exosomal miR-770 markedly decreased NSCLC tumor growth in vivo through suppressing M2 macrophage polarization.

Conclusion

Tumor cell-derived exosomal miR-770 inhibits M2 macrophage polarization to inhibit the invasion of NSCLC cells via targeting MAP3K1. Thus, this study provided a new strategy for the treatment of NSCLC.

Characteristics and possible mechanisms of 46, XY differences in sex development caused by novel compound variants in NR5A1 and MAP3K1

Background

Dozens of genes are involved in 46, XY differences in sex development (DSD). Notably, about 3/4 of patients cannot make a clear etiology diagnosis and single gene variant identified cannot fully explain the clinical heterogeneity of 46, XY DSD.

Materials and methods

We conducted a systematic clinical analysis of a 46, XY DSD patient, and applied whole-exome sequencing for the genetic analysis of this pedigree. The identified variants were analyzed by bioinformatic analysis and in vitro studies were performed in human embryonic kidney 293T (HEK-293T) cells which were transiently transfected with wild type or variant NR5A1 and MAP3K1 plasmid. Furthermore, protein production of SRY-box transcription factor 9 (SOX9) was analyzed in cell lysates.

Results

A novel NR5A1 variant (c.929A > C, p. His310Pro) and a rare MAP3K1 variant (c.2282T > C, p. Ile761Thr) were identified in the proband, whereas the proband's mother and sister who only carry rare MAP3K1 variant have remained phenotypically healthy to the present. These two variants were predicted to be pathogenic by bioinformatic analysis. In vitro, NR5A1 variant decreased the SOX9 production by 82.11% compared to wild type NR5A1, while MAP3K1 variant had little effect on the SOX9 production compared to wild type MAP3K1. Compared to wild type NR5A1 transfection, the SOX9 production of cells transfected with both wild type plasmids decreased by about 17.40%. Compared to variant NR5A1 transfection, the SOX9 production of cells transfected with both variant plasmids increased by the 36.64%.

Conclusions

Our findings suggested the novel compound variants of NR5A1 and MAP3K1 can alter the expression of SOX9 and ultimately lead to abnormality of sex development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01908-z.

First case of ductal adenocarcinoma of the prostate with MAP3K1 homozygous deletion

INTRODUCTION

Ductal adenocarcinoma of the prostate is a rare prostate cancer variant and associated with higher stage and greater risk of mortality. Optimal systemic therapy for metastatic ductal adenocarcinoma is not known.

CASE PRESENTATION

A 67-year-old man presented with ductal adenocarcinoma of the prostate accompanied by multiple lung metastases and advanced bone metastases. We performed channel transurethral resection of the prostate and confirmed the diagnosis of ductal adenocarcinoma of the prostate. DNA sequencing identified a TP53 somatic point mutation (p.Gly245Ser) as the pathogenic variant. Furthermore, a homozygous deletion was observed in mitogen-activated protein kinase kinase kinase 1. The patient received enzalutamide but deceased 5 months after presenting to our institution.

CONCLUSION

To our knowledge, this is the first report of ductal adenocarcinoma of the prostate with a mitogen-activated protein kinase kinase kinase 1 homozygous deletion. Accumulation of whole-exome sequencing data is expected to inform future advances in therapy development.

LncRNA NEAT1 promotes malignant phenotypes and TMZ resistance in glioblastoma stem cells by regulating let-7g-5p/MAP3K1 axis

Glioblastoma multiforme (GBM) is one of the most malign brain tumors in adults. Temozolomide (TMZ) is an oral chemotherapy drug constituting the backbone of chemotherapy regimens utilized as first-line treatment of GBM. However, resistance to TMZ often leads to treatment failure. In the present study, we explored the expression and related mechanisms of nuclear enriched abundant transcript 1 (NEAT1) in glioma stem cells (GSCs). Quantitative real-time PCR (qRT-PCR) showed that NEAT1 was up-regulated in serum samples of GBM patients and GSCs isolated from U87, U251 cell lines. Functional experiments showed that NEAT1 knockdown restrained malignant behaviors of GSC, including proliferation, migration and invasion. Dual-luciferase assays identified let-7g-5p was a downstream target and negatively adjusted by NEAT1. Restoration of let-7g-5p impeded tumor progression by inhibiting proliferation, migration and invasion. Mitogen-activated protein kinase kinase kinase 1 (MAP3K1), as a direct target of let-7g-5p, was positively regulated by NEAT1 and involved to affect the regulation of NEAT1 on GSCs' behaviors. In conclusion, our results suggested that NEAT1 promoted GSCs progression via NEAT1/let-7g-5p/MAP3K1 axis, which provided a depth insight into TMZ resistance mechanism.

Silencing MAP3K1 expression inhibits the proliferation of goat hair follicle stem cells

The Yangtze River Delta White Goat is the only goat breed in the world that can produce superior-quality brush hair. Previous studies have shown that some genes are expressed differentially in the skin tissues between the goats produced superior-quality and normal-quality brush hair. Studies also have shown that different gene play varied roles in regulating the proliferation and apoptosis of hair follicle stem cells. However, the biological function of MAP3K1 (mitogen-activated protein kinase kinase kinase 1) gene in hair follicle stem cells is not fully understood. This study aims to investigate the role of MAP3K1 knockdown during the proliferation and apoptosis of hair follicle stem cells. RT-qPCR and Western blot were used to detect mRNA gene and protein expression level, CCK-8 and EdU assays were used to detect cell proliferation, and cell cycle and apoptosis were detected by flow cytometry. The results showed that the MAP3K1 expression level was significantly higher in the skin tissue of produced superior-quality brush hair than that in produced normal-quality brush hair. Moreover, functional studies indicated that si-MAP3K1 significantly inhibits the proliferation of hair follicle stem cells that came from a superior goat and promotes its apoptosis. Based on aforementioned assays, we speculated that MAP3K1 might play a regulatory effect in superior-quality brush hair traits.

miR-31-5p promotes proliferation and inhibits apoptosis of goat hair follicle stem cells by targeting RASA1/MAP3K1 pathway

The Yangtze River Delta white goat is a sole goat species that can naturally produce superior-quality brush hair. It's worth to mention that study the developmental mechanism of goat hair follicle stem cells is vital for future breed preservation and molecular breeding. In this study, we successfully isolated hair follicle stem cells from the skin tissue of fetal sheep neck spine, and harvested superior-quality and normal-quality brush hair goat tissue. The expression of miR-31-5p in goat hair follicle stem cells was verified by qPCR and Western blot. The effects of overexpression or inhibition of miR-31-5p on the proliferation and apoptosis of hair follicle stem cells were detected by EdU, CCK-8, flow cytometry, etc. miR-31-5p can significantly improve cell proliferation and inhibit cell apoptosis by targeting RASA1 and upregulating MAP3K1 level, whereas miR-31-5p knockdown led to an opposite effect. These results reveal a miR-31-5p-associated regulatory network between miR-31-5p and RASA1/MAP3K1 during the progression of superiorquality brush hair traits.

Long noncoding RNA FOXD2-AS1 aggravates hepatocellular carcinoma tumorigenesis by regulating the miR-206/MAP3K1 axis

LncRNAs play crucial roles in the development of various cancers including hepatocellular carcinoma (HCC). Nevertheless, the function of the long noncoding RNA (lncRNA) FOXD2‐AS1 in HCC is still poorly understood. In this study, we focused on the role of FOXD2‐AS1 in HCC. We found that FOXD2‐AS1 was significantly upregulated in HCC cells in comparison to normal human liver cells, LO2. In this study, we also demonstrated that miR‐206 expression was greatly reduced in HCC cells. Furthermore, the inhibition of FOXD2‐AS1 repressed HCC cell proliferation, enhanced cell apoptosis, and restrained cell invasion and migration. The knockdown of FOXD2‐AS1 elevated miR‐206 expression, and we validated an interaction between these RNAs. Additionally, miR‐206 mimics inhibited HCC development while miR‐206 mimics had the opposite effect. MAP kinase 1 (MAP3K1) was predicted to be a target of miR‐206. We discovered that FOXD2‐AS1 modulated MAP3K1 expression by sponging miR‐206 in MHCC‐97L and HepG2 cells. Finally, our in vivo experiments validated that the knockdown of FOXD2‐AS1 inhibited HCC progression by modulating the miR‐206/MAP3K1 axis. In conclusion, this work implies FOXD2‐AS1 accelerates HCC progression through sponging miR‐206 and regulating MAP3K1 expression.

miR-203 affects esophageal cancer cell proliferation, apoptosis and invasion by targeting MAP3K1

miR-203 has been indicated to be a tumor suppressor in esophageal cancer, however, the underlying molecular mechanisms by which it functions are not fully understood. The present study aimed to investigate the molecular mechanisms underlying the regulatory activities of microRNA (miR)-203 in esophageal cancer. The miR-203 mimic/inhibitor, Mitogen-Activated Protein Kinase Kinase Kinase 1 (MAP3K1) overexpression plasmid and MAP3K1 small interfering (si)RNA were transfected into TE-1 cells. miR-203 and MAP3K1 mRNA expression were detected via reverse transcription-quantitative PCR analysis, while MAP3K1 protein expression was detected via western blot analysis. Dual-luciferase reporter assay was used to determine whether MAP3K1 was a direct target of miR-203. Cell proliferation and invasion abilities were assessed via MTT and Matrigel assays, respectively. Cell apoptosis was analyzed via flow cytometry, Caspase 8/3 Assay kits and western blot analysis. The results demonstrated that MAP3K1 was a direct target of miR-203. Overexpression of MAP3K1 reversed the suppressed cell proliferation and invasion abilities induced by miR-203 mimic, as well as the inhibitory effect of miR-203 mimic on cell apoptosis. Furthermore, MAP3K1 siRNA weakened the effect of miR-203 inhibitor on cell proliferation, apoptosis and invasion.

gga-miR-21 modulates Mycoplasma gallisepticum (HS strain)-Induced inflammation via targeting MAP3K1 and activating MAPKs and NF-κB pathways

Mycoplasma gallisepticum (MG) can target host cells and cause chronic respiratory disease (CRD) in chickens that is characterized by pMGA and concomitant. Although microRNAs (miRNAs) have been manifested are crucial regulatory noncoding RNAs with important effects on microbial pathogenesis and inflammatory response, how miRNAs regulate MG-induced inflammation remains to be discovered. The results showed that gga-miR-21 was up-regulated in MG-infected chicken embryonic lungs and MG infection of chicken embryo fibroblast cells (DF-1) compared with the control group. Overexpression of gga-miR-21 increased the inflammatory cytokines production, including tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and interleukin-8 (IL-8) after MG infection, knockdown of gga-miR-21 had thoroughly inverse effects. Gene expression data combined with bioinformatics analysis and luciferase reporter assays demonstrated that mitogen-activated protein kinase kinase kinase 1(MAP3K1) was a novel target of gga-miR-21. The inhibition of MAP3K1 by gga-miR-21 resulted in the accumulation of NF-κB in the nucleus, which in turn generate higher inflammatory cytokines. Furthermore, upregulation of gga-miR-21 significantly inhibited MG propagation and promoted MG-infected DF-1 cells proliferation by increasing the cell cycle progression and suppressing cell apoptosis. Our study provides evidence for proinflammatory effects of gga-miR-21 which is mediated at least in part by targeting MAP3K1 in the MG-infected DF-1 cells. gga-miR-21 activates MAPKs and NF-κB signaling pathways via targeting MAP3K1, and then promotes the production of inflammatory cytokines and cell proliferation by increasing the cell cycle progression and suppressing cell apoptosis to defend against MG infection.

Novel pathogenic mutations in disorders of sex development associated genes cause 46,XY complete gonadal dysgenesis

Disorders of sex development (DSDs) are congenital conditions in which chromosomal, gonadal and sex is atypical. It is difficult to diagnose and manage patients with DSD in clinical practice, and the molecular etiology of DSD is still not completely understood. Here, we identified two novel pathogenic mutations from three unrelated Chinese patients with 46,XY complete gonadal dysgenesis (CGD) that is a clinical subgroup of DSD by whole exome sequencing. A novel mutation in the SRY gene (c.161delG) was identified in the first patient, and the second patient carried a novel missense mutation in the MAP3K1 gene (c.2117T>G). Bioinformatics analysis found that the deletion of SRY (c.161delG) led to a premature stop codon at amino acid 59 in the SRY protein, which resulted in lacking the DNA binding domain of SRY protein. Functional studies found that the missense mutation in the MAP3K1 gene (c.2117T>G) could interfere with the gene function through increasing the phosphorylation of the downstream targets of MAP3K1, ERK1/2 and p38, which resulted in reducing testis-determining factor SOX9 expression and increasing ovary-promoting factor β-catenin activity. According to the American college of medical genetics and genomics (ACMG) standards and guidelines, these mutations were categorized as "pathogenic" mutations. Thus, our findings provide two novel pathogenic mutations associated with 46,XY CGD that can improve the etiological diagnosis for 46,XY CGD. ABBREVIATIONS.

Combined elevation of TRIB2 and MAP3K1 indicates poor prognosis and chemoresistance to temozolomide in glioblastoma

Introduction

Glioblastoma (GBM) is the most lethal primary malignant brain tumor in adults with poor survival due to acquired therapeutic resistance and rapid recurrence. Currently, the standard clinical strategy for glioma includes maximum surgical resection, radiotherapy, and temozolomide (TMZ) chemotherapy; however, the median survival of patients with GBM remains poor despite these comprehensive therapies. Therefore, the identification of new prognostic biomarkers is urgently needed to evaluate the malignancy and long‐term outcome of glioma.

Aims

To further investigate prognostic biomarkers and potential therapeutic targets for GBM.

Results

In this study, we identified tribbles pseudokinase 2 (TRIB2) as one of the genes that is most correlated with pathological classification, radioresistance, and TMZ resistance in glioma. Additionally, the expression of mitogen‐activated protein kinase kinase kinase 1 (MAP3K1) showed a strong correlation with TRIB2. Moreover, a combined increase in TRIB2 and MAP3K1 was observed in GBM and indicated a poor prognosis of patients with glioma. Finally, enriched TRIB2 expression and MAP3K1 expression were shown to be associated with resistance to TMZ and radiotherapy.

Conclusion

Combined elevation of TRIB2 and MAP3K1 could be novel prognostic biomarkers and potential therapeutic targets to evaluate the malignancy and long‐term outcomes of GBM.

miR-196b inhibits cell migration and invasion through targeting MAP3K1 in hydatidiform mole

MicroRNAs (miRNAs) are a class of small non-coding RNAs that are closely associated with carcinogenesis. Accumulating data indicate that miR-196b participates in the development of various types of cancers. However, the role of miR-196b in the formation of hydatidiform mole (HM) is still unclear. Our previous studies have demonstrated that miR-196b levels were decreased in JAR and BeWo cells and in HM tissue samples, as demonstrated by RT-PCR analysis. Furthermore, we discovered that overexpression of miR-196b in JAR and BeWo cells inhibited cellular proliferation, migration and invasion, as shown by Cell counting kit-8 (CCK-8) and transwell assays, respectively. Subsequently, we explored the interaction of miR-196b with its target gene in human choriocarcinoma cell lines. MAP3K1 is a target gene predicted by bioinformatic analysis that was previously shown to exhibit reduced expression levels following treatment with miR-196b in JAR and BeWo cells. We demonstrated that MAP3K1 was a direct target of miR-196b using the dual-luciferase reporter assay in Hela cells. In summary, the present study demonstrated that miR-196b suppressed proliferation, migration and invasion of human choriocarcinoma cells by inhibiting its transcriptional target MAP3K1. miR-196b and MAP3K1 may be considered potential targets for the clinical treatment of HM.

Characterization of frequently mutated cancer genes in Chinese breast tumors: a comparison of Chinese and TCGA cohorts

Background

The complexity of breast cancer at the clinical, morphological and genomic levels has been extensively studied in the western population. However, the mutational genomic profiles in Chinese breast cancer patients have not been explored in any detail.

Methods

We performed targeted sequencing using a panel consisting of 33 breast cancer-related genes to investigate the genomic landscape of 304 consecutive treatment-naïve Chinese breast cancer patients at Guangdong Provincial People's Hospital (GDPH), and further compared the results to those in 453 of Caucasian breast cancer patients from The Cancer Genome Atlas (TCGA).

Results

The most frequently mutated gene was TP53 (45%), followed by PIK3CA (44%), GATA3 (18%), MAP3K1 (10%), whereas the copy-number amplifications were frequently observed in genes of ERBB2 (24%), MYC (23%), FGFR1 (13%) and CCND1 (10%). Among the 8 most frequently mutated or amplified genes, at least one driver was identifiable in 87.5% (n=267) of our GDPH cohort, revealing the significant contribution of these known driver genes in the development of Chinese breast cancer. Compared to TCGA data, the median age at diagnosis in our cohort was significantly younger (48 vs. 58 years; P<0.001), while the distribution of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2) statuses were similar. The largest difference occurred in HR+/HER2- subtype, where 8 of the 10 driver genes compared had statistically significant differences in their frequency, while there were differences in 2 of 10 driver genes among the TNBC and HR+/HER2+ group, but none in the HR-/HER2+ patients in our cohort compared to the TCGA data. Collectively, the most significant genomic difference was a significantly higher prevalence for TP53 and AKT1 in Chinese patients. Additionally, more than half of TP53-mutation HR+/HER2- Chinese patients (~60%) are likely to harbor more severe mutations in TP53, such as nonsense, indels, and splicing mutations.

Conclusions

We elucidated the mutational landscape of cancer genes in Chinese breast cancer and further identified significant genomic differences between Asian and Caucasian patients. These results should improve our understanding of pathogenesis and/or metastatic behavior of breast cancer across races/ethnicities, including a better selection of targeted therapies.

Repression of MAP3K1 expression and JNK activity by canonical Wnt signaling

Morphogenesis is a complex and highly coordinated process orchestrated by temporal spatial activity of developmental pathways. How the different pathways interact to guide the developmental program remains an intriguing and open question. MAP3K1-JNK and Wnt are signaling pathways crucial for embryonic eyelid closure, an epithelial morphogenetic event conserved in mammals. Here we used a mouse model of eyelid development and genetic and biochemistry tools to investigate the relationships between the two pathways. We found that Wnt activation repressed MAP3K1 expression. Using Axin-LacZ reporter mice, spatial Wnt activity was detected in the leading edge of the developing eyelid. Conditional knockout of Wntless (Wls) in ocular surface ectoderm blocked eyelid formation, and significantly increased MAP3K1 expression in eyelid cells at the nasal canthus region. Conversely, knockout of Dkk2, encoding a canonical Wnt antagonist, resulted in an increase of Wnt activity in cells at the upper eyelid margin near the nasal canthus. Up-regulation of Wnt signaling in the Dkk2-knockout embryos corresponded to down-regulation of MAP3K1 expression. In vitro data showed that Wnt3a treatment decreased MAP3K1 promoter activity, whereas activation of Wnt by lithium chloride inhibited MAP3K1 expression, and attenuated MAP3K1-mediated JNK activity. Our data identify a unique signal crosstalk between Wnt signaling and the MAP3K1-JNK pathway in epithelial morphogenesis.

Functional significance of co-occurring mutations in PIK3CA and MAP3K1 in breast cancer

The PI3Kα signaling pathway is frequently hyper-activated in breast cancer (BrCa), as a result of mutations/amplifications in oncogenes (e.g. HER2), decreased function in tumor suppressors (e.g. PTEN) or activating mutations in key components of the pathway. In particular, activating mutations of PIK3CA (~45%) are frequently found in luminal A BrCa samples. Genomic studies have uncovered inactivating mutations in MAP3K1 (13-20%) and MAP2K4 (~8%), two upstream kinases of the JNK apoptotic pathway in luminal A BrCa samples. Further, simultaneous mutation of PIK3CA and MAP3K1 are found in ~11% of mutant PIK3CA tumors. How these two alterations may cooperate to elicit tumorigenesis and impact the sensitivity to PI3K and AKT inhibitors is currently unknown. Using CRISPR gene editing we have genetically disrupted MAP3K1 expression in mutant PIK3CA cell lines to specifically create in vitro models reflecting the mutational status of PIK3CA and MAP3K1 in BrCa patients. MAP3K1 deficient cell lines exhibited ~2.4-fold increased proliferation rate and decreased sensitivity to PI3Kα/δ(AZD8835) and AKT (AZD5363) inhibitors (~2.61 and ~5.23-fold IC₅₀ increases, respectively) compared with parental control cell lines. In addition, mechanistic analysis revealed that MAP3K1 disruption enhances AKT phosphorylation and downstream signaling and reduces sensitivity to AZD5363-mediated pathway inhibition. This appears to be a consequence of deficient MAP3K1-JNK signaling increasing IRS1 stability and therefore promoting IRS1 binding to p85, resulting in enhanced PI3Kα activity. Using 3D-MCF10A-PI3Kα^H1047R models, we found that MAP3K1 depletion increased overall acinar volume and counteracted AZD5363-mediated reduction of acinar growth due to enhanced proliferation and reduced apoptosis. Furthermore, in vivo efficacy studies revealed that MAP3K1-deficient MCF7 tumors were less sensitive to AKT inhibitor treatment, compared with parental MCF7 tumors. Our study provides mechanistic and in vivo evidence indicating a role for MAP3K1 as a tumor suppressor gene at least in the context of PIK3CA-mutant backgrounds. Further, our work predicts that MAP3K1 mutational status may be considered as a predictive biomarker for efficacy in PI3K pathway inhibitor trials.

MTDH and MAP3K1 are direct targets of apoptosis-regulating miRNAs in colorectal carcinoma

Artificially designed miRNAs mimics and inhibitors that specifically target known oncogenes have attracted significant research attention. Herein, we aimed to explore whether MIR-375, MIR-145, and MIR-224 are involved in induction of apoptosis of CRC cells by regulating apoptosis-mediating genes MTDH, MAP3K1, PDK1, BAX, and BCL-XL. MTT assay was used to assess cell growth. Apoptosis was determined in terms of caspase activity measurement and phosphatidylserine detection using annexin V staining by flow cytometry. Quantitative real time PCR, Western blotting, and luciferase reporter assay were carried out to validate genes regulation and targeting by miRNAs. We found that ectopic expression of MIR-375 and MIR-145, and inhibition of MIR-224 can decrease cell growth and induce cell ability to undergo early apoptosis. At mRNA level, transfected cells displayed down-regulation of MTDH, PDK1 and BCL-XL, while BAX and MAP3K1 were up-regulated. Protein expression of MTDH was decreased in cells transfected with MIR-145 mimic and MIR-224 inhibitor but remained unchanged in MIR-375 mimic-transfected cells. Furthermore, MAP3K1 protein expression exibited a decreased level after MIR-375 transient expression with no significant change after MIR-145 mimic or MIR-224 inhibitor transfection. Luciferase reporter assay revealed that MIR-375 and MIR-145 can bind to 3'UTR of MTDH, supporting that MTDH is directly targeted by both miRNAs. Similarly, MAP3K1 was found to be directly regulated by MIR-375. The study concluded that the expression modulation of tumor suppressors MIR-375 and MIR-145, and oncomiR MIR-224 have the ability to induce apoptosis of CRC cells through regulation of apoptosis mediating genes MTDH, MAP3K1, PDK1, BCL-XL and BAX.

MAP3K1-related gonadal dysgenesis: Six new cases and review of the literature

Investigation of disorders of sex development (DSD) has resulted in the discovery of multiple sex-determining genes. MAP3K1 encodes a signal transduction regulator in the sex determination pathway and is emerging as one of the more common genes responsible for 46,XY DSD presenting as complete or partial gonadal dysgenesis. Clinical assessment, endocrine evaluation, and genetic analysis were performed in six individuals from four unrelated families with 46,XY DSD. All six individuals were found to have likely pathogenic MAP3K1 variants. Three of these individuals presented with complete gonadal dysgenesis, characterized by bilateral streak gonads with typical internal and external female genitalia, while the other three presented with partial gonadal dysgenesis, characterized by incomplete testicular development, resulting in clitoral hypertrophy with otherwise typical female external genitalia. Testing for MAP3K1 variants should be considered in patients with 46,XY complete or partial gonadal dysgenesis, particularly in families with multiple members affected with 46,XY DSD. Identification of a MAP3K1 variant should prompt an evaluation for DSD in female siblings of the proband.

MAP3K1 May be a Promising Susceptibility Gene for Type 2 Diabetes Mellitus in an Iranian Population

Considering that MAPK (mitogen- activated protein kinase) signaling pathway has an important role in the progression of inflammatory cytokine secretion in type 2 diabetes mellitus (T2DM), we have recently investigated the reported genetic polymorphism from genome wide association study in MAP3K1 (mitogen-activated protein kinase kinase kinase 1) in diabetes as an important member of MAPK signaling. This study aimed to investigate the possible association of rs10461617 at the upstream of MAP3K1 gene in an Iranian case-control study with the risk of T2DM. The study population was comprised of 342 unrelated Iranian individuals including 177 patients with T2DM and 165 unrelated healthy control subjects. Genotyping was performed using PCR-RFLP and confirmed with sequencing. In a logistic regression analysis, the rs10461617A allele was associated with a significantly higher risk of T2DM assuming the log- additive model (OR: 1.44, 95% CI: 1.01-2.05, P = 0.039). In conclusion, we provided the first evidence for the association of rs10461617 at the upstream of MAP3K1 with the risk of T2DM in an Iranian population.

MAP3K1-targeting therapeutic artificial miRNA suppresses the growth and invasion of breast cancer in vivo and in vitro

Recent investigations have highlighted that therapeutic artificial microRNAs could be promising candidates for cancer therapy through the modulation of tumor promoter or suppressor. MEK kinase 1 (MEKK1) is expressed by mitogen-activated kinase kinase kinase 1 (MAP3K1), an important kinase that links Ras activation to MAPK signaling. In the present study, we showed that synthetic MAP3K1-targeting artificial miRNA may provide considerable beneficial effects in the prevention of breast cancer growth and metastasis. We showed that MEKK1 was highly expressed in human breast cancer specimens, compared with adjacent normal tissues. Using a miRNA-expressing lentivirus system, we delivered a artificial miRNA (Map3k1 amiRNA) that targets MAP3K1 into 4T1 breast cancer cells and investigated the impact of MAP3K1-targeting miRNA on the growth and invasive behavior of breast cancer in vitro and in vivo. We found that overexpression of Map3k1 amiRNA led to impaired activities of p-ERK and p-p38. In addition, Map3k1 amiRNA induced marked proliferative impairment and invasive attenuation in breast cancer cells. However, Map3k1 amiRNA did not have evident influence on the apoptotic response of 4T1 cells. Moreover, using in vivo nude mice model, we identified that Map3k1 amiRNA attenuated tumor growth and lung metastasis of breast cancer cells. Taken together, our findings explicitly indicated that MEKK1 exerted important oncogenic property in breast cancer development, and MAP3K1-targeting artificial miRNA may provide promising therapeutic effects in the treatment of breast cancer.

The goya mouse mutant reveals distinct newly identified roles for MAP3K1 in the development and survival of cochlear sensory hair cells

Mitogen-activated protein kinase, MAP3K1, plays an important role in a number of cellular processes, including epithelial migration during eye organogenesis. In addition, studies in keratinocytes indicate that MAP3K1 signalling through JNK is important for actin stress fibre formation and cell migration. However, MAP3K1 can also act independently of JNK in the regulation of cell proliferation and apoptosis. We have identified a mouse mutant, goya, which exhibits the eyes-open-at-birth and microphthalmia phenotypes. In addition, these mice also have hearing loss. The goya mice carry a splice site mutation in the Map3k1 gene. We show that goya and kinase-deficient Map3k1 homozygotes initially develop supernumerary cochlear outer hair cells (OHCs) that subsequently degenerate, and a progressive profound hearing loss is observed by 9 weeks of age. Heterozygote mice also develop supernumerary OHCs, but no cellular degeneration or hearing loss is observed. MAP3K1 is expressed in a number of inner-ear cell types, including outer and inner hair cells, stria vascularis and spiral ganglion. Investigation of targets downstream of MAP3K1 identified an increase in p38 phosphorylation (Thr180/Tyr182) in multiple cochlear tissues. We also show that the extra OHCs do not arise from aberrant control of proliferation via p27KIP1. The identification of the goya mutant reveals a signalling molecule involved with hair-cell development and survival. Mammalian hair cells do not have the ability to regenerate after damage, which can lead to irreversible sensorineural hearing loss. Given the observed goya phenotype, and the many diverse cellular processes that MAP3K1 is known to act upon, further investigation of this model might help to elaborate upon the mechanisms underlying sensory hair cell specification, and pathways important for their survival. In addition, MAP3K1 is revealed as a new candidate gene for human sensorineural hearing loss.

Summary: The ENU-derived mouse mutant goya, reveals, for the first time, multiple roles of MAP3K1 in cochlear development and correct auditory function.

Let-7g induces granulosa cell apoptosis by targeting MAP3K1 in the porcine ovary

Follicular atresia mainly results from apoptosis of granulosa cells (GCs). Our previous microRNA array data indicated that the miRNA let-7g level increases significantly during porcine ovary follicular atresia. It is uncertain if GCs apoptosis is mediated by microRNA let-7g. In this study, the expression levels of the apoptosis-associated genes CASP3, BAX and BIM were significantly upregulated when let-7g mimic was transfected into porcine GCs, and the anti-apoptotic genes BCL-2 and MCL-1 were significantly downregulated. The apoptosis rate was measured by flow cytometry, and our results indicated that let-7g significantly enhanced GCs apoptosis. In further studies, we found that overexpression of let-7g induced the expression of FoxO1 in GCs and led to nuclear accumulation of dephosphorylated FoxO1. In addition, the effect of let-7g on FoxO1 expression and dephosphorylation resulted from repression of the expression of the MAP3K1 gene in porcine GCs. The site on MAP3K1 mRNA targeted by let-7g was confirmed by luciferase reporter assay. The anti-apoptotic effect of MAP3K1 was validated by silencing MAP3K1 using small interfering RNA technology. In conclusion, our data indicate that let-7g induces porcine GCs apoptosis by inhibiting the MAP3K1 gene, which promotes FoxO1 expression and dephosphorylation with nuclear accumulation.

MiR-451 inhibits proliferation of esophageal carcinoma cell line EC9706 by targeting CDKN2D and MAP3K1

AIM: To investigate the underlying molecular mechanisms of miR-451 to inhibit proliferation of esophageal carcinoma cell line EC9706.

METHODS: Assays for cell growth, apoptosis and invasion were used to evaluate the effects of miR-451 expression on EC cells. Luciferase reporter and Western blot assays were used to test whether cyclin-dependent kinase inhibitor 2D (CDKN2D) and MAP3K1 act as major targets of miR-451.

RESULTS: The results showed that CDKN2D and MAP3K1 are direct targets of miR-451. CDKN2D and MAP3K1 overexpression reversed the effect of miR-451. MiR-451 inhibited the proliferation of EC9706 by targeting CDKN2D and MAP3K1.

CONCLUSION: These findings suggest that miR-451 might be a novel prognostic biomarker and a potential target for the treatment of esophageal squamous cell carcinoma in the future.

Epithelial sheet movement requires the cooperation of c-Jun and MAP3K1

Epithelial sheet movement is an essential morphogenetic process during mouse embryonic eyelid closure in which Mitogen-Activated Protein 3 Kinase 1 (MAP3K1) and c-Jun play a critical role. Here we show that MAP3K1 associates with the cytoskeleton, activates Jun N-terminal kinase (JNK) and actin polymerization, and promotes the eyelid inferior epithelial cell elongation and epithelium protrusion. Following epithelium protrusion, c-Jun begins to express and acts to promote ERK phosphorylation and migration of the protruding epithelial cells. Homozygous deletion of either gene causes defective eyelid closure, but non-allelic non-complementation does not occur between Map3k1 and c-Jun and the double heterozygotes have normal eyelid closure. Results from this study suggest that MAP3K1 and c-Jun signal through distinct temporal-spatial pathways and that productive epithelium movement for eyelid closure requires the consecutive action of MAP3K1-dependent cytoskeleton reorganization followed by c-Jun-mediated migration.

Adiposity, inflammation, genetic variants and risk of post-menopausal breast cancer findings from a prospective-specimen-collection, retrospective-blinded-evaluation (PRoBE) design approach

Chronic internal inflammation secondary to adiposity is a risk factor for sporadic breast cancer and Post-Menopausal Breast Cancer (PMBC) is largely defined as such. Adiposity is one of the clinical criteria for the diagnosis of Metabolic Syndrome (MetS) and is a risk factor for PMBC. We examined SNPs of eight genes implicated in adiposity, inflammation and cell proliferation in a Prospective-specimen-collection, Retrospective-Blinded-Evaluation (PRoBE) design approach. A total of 180 cases and 732 age-matched controls were identified from the MyCode prospective biobank database and then linked to the Clinical Decision Information System, an enterprise-wide data warehouse, to retrieve clinico-demographic data. Samples were analyzed in a core laboratory where the personnel were masked to their status. Results from multivariate logistic regression yielded one SNP (rs2922126) in the GHSR as protective against PMBC among homozygotes for the minor allele (A/A) (OR = 0.4, 95% CI 0.18-.89, P-value = .02); homozygosity for the minor allele (C/C) of the SNP (rs889312) of the gene MAP3K1 was associated with the risk of PMBC (OR = 2.41, 95% CI 1.25-4.63 P-value = .008). Advanced age was protective against PMBC (OR = 0.98, 95% CI 0.95-0.99, P-value = .02). Family history of breast cancer (OR = 2.22, 95% CI 1.14-4.43. P = .02), HRT (OR = 3.35; 95% CI 2.15-5.21, P < .001), and MetS (OR = 14.83, 95% CI 5.63-39.08, P < .001) and interaction between HRT and MetS (OR = 39.38, 95% CI 15.71-98.70, P < .001) were associated with the risk of PMBC. We did not detected significant interactions between SNPs or between the SNPs and the clinico-demographic risk factors. Our study further confirms that MetS increases the risk of PMBC and argues in favor of reducing exposure to HRT. Our findings are another confirmation that low penetrance genes involved in the inflammatory pathway, i.e. MAP3KI gene, may have a plausible causative role in PMBC. Given the fact that genetic constitutionality of individuals cannot be changed, efforts should be focused on life style modification.