WWC3 inhibits epithelial-mesenchymal transition of lung cancer by activating Hippo-YAP signaling

Bioinformatic miRNA-mRNAs Analysis Revels to miR-934 as a Potential Regulator of the Epithelial-Mesenchymal Transition in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is one of the most aggressive subtypes of breast cancer and has the worst prognosis. In patients with TNBC tumors, the tumor cells have been reported to have mesenchymal features, which help them migrate and invade. Various studies on cancer have revealed the importance of microRNAs (miRNAs) in different biological processes of the cell in that aberrations, in their expression, lead to alterations and deregulations in said processes, giving rise to tumor progression and aggression. In the present work, we determined the miRNAs that are deregulated in the epithelial-mesenchymal transition process in breast cancer. We discovered that 25 miRNAs that regulate mesenchymal genes are overexpressed in patients with TNBC. We found that miRNA targets modulate different processes and pathways, such as apoptosis, FoxO signaling pathways, and Hippo. We also found that the expression level of miR-934 is specific to the molecular subtype of the triple-negative breast cancer and modulates a set of related epithelial-mesenchymal genes. We determined that miR-934 inhibition in TNBC cell lines inhibits the migratory abilities of tumor cells.

Deciphering the role of Hippo pathway in lung cancer

Hippo pathway has been initially recognized as a regulatory mechanism for modulation of organ size in fruitfly. Subsequently, its involvement in the regulation of homeostasis and tumorigenesis has been identified. This pathway contains some tumor suppressor genes such as hippo (hpo) and warts (wts), as well as a number of oncogenic ones such as yorkie (yki). Recent studies have shown participation of Hippo pathway in the lung carcinogenesis. This pathway can affect lung cancer via different mechanisms. The interaction between some miRNAs and Hippo pathway is a possible mechanism for carcinogenic processes. Moreover, some other types of non-coding RNAs including PVT1, SFTA1P, NSCLCAT1 and circ_0067741 are implicated in this process. Besides, anti-cancer effects of gallic acid, icotinib hydrochloride, curcumin, ginsenoside Rg3, cryptotanshinone, nitidine chloride, cucurbitacin E, erlotinib, verteporfin, sophoridine, cisplatin and verteporfin in lung cancer are mediated through modulation of Hippo pathway. Here, we summarize the results of recent studies that investigated the role of Hippo signaling in the progression of lung cancer, the impact of non-coding RNAs on this pathway and the effects of anti-cancer agents on Hippo signaling in the context of lung cancer.

Antitumor Activity of lncRNA NBAT-1 via Inhibition of miR-4504 to Target to WWC3 in Oxaliplatin-Resistant Colorectal Carcinoma

Background

Increasing evidence shows that dysfunction of noncoding RNAs is implicated in cancer. Neuroblastoma associated transcript 1 (NBAT-1) has been identified as a tumor suppressive lncRNA that is aberrantly expressed in cancers. However, the function and the underlying mechanisms of the NBAT-1 in colorectal carcinoma (CRC) remain unknown.

Methods

Gene expression was detected by RT-qPCR. The influence of NBAT-1 on CRC was evaluated by the cell counting kit-8 (CCK-8) assay and an in vivo xenograft mouse model. The possible binding of NBAT-1 to miRNAs was predicted via the miRDB online tool and confirmed by a dual-luciferase reporter assay. Protein expression was detected by western blot.

Results

NBAT-1 expression was significantly decreased in CRC tissues, especially in patients with oxaliplatin (OXA) resistance. NBAT-1 inhibited OXA-resistant CRC cell proliferation in vitro and tumor growth in vivo. The mechanism study revealed that NBAT-1 functioned as a competing endogenous RNA (ceRNA) of miR-4504. NBAT-1 bound miR-4504 and decreased miR-4504 expression in CRC cells. Furthermore, WW-and-C2-domain-containing protein family member 3 (WWC3) was identified as a target of miR-4504. Downregulation of NBAT-1 promoted miR-4504 expression and reduced the level of WWC3. Inhibition of WWC3 by NBAT-1 depletion inactivated Hippo signalling by inhibiting the phosphorylation of large tumor suppressor kinase 1 (LATS1) and yes-associated protein (YAP). Consistently, knockdown of NBAT-1 suppressed the expression of YAP transcriptional targets.

Conclusions

These findings demonstrated that lncRNA NBAT-1 suppresses OXA-resistant CRC cell growth via inhibition of miR-4504 to regulate the WWC3/LATS1/YAP axis.

Proteomic Analysis of Endometrial Cancer Tissues from Patients with Type 2 Diabetes Mellitus

Endometrial cancer (EC) is the most common form of gynecological cancer. Type 2 diabetes mellitus is associated with an increased risk of EC. Currently, no proteomic studies have investigated the role of diabetes in endometrial cancers from clinical samples. The present study aims to elucidate the molecular link between diabetes and EC using a proteomic approach. Endometrial tissue samples were obtained from age-matched patients (EC Diabetic and EC Non-Diabetic) during surgery. Untargeted proteomic analysis of the endometrial tissues was carried out using a two-dimensional difference in gel electrophoresis (2D-DIGE) coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF). A total of 53 proteins were identified, with a significant difference in abundance (analysis of variance (ANOVA) test, p ≤ 0.05; fold-change ≥ 1.5) between the two groups, among which 30 were upregulated and 23 downregulated in the EC Diabetic group compared to EC Non-Diabetic. The significantly upregulated proteins included peroxiredoxin-1, vinculin, endoplasmin, annexin A5, calreticulin, and serotransferrin. The significantly downregulated proteins were myosin regulatory light polypeptide 9, Retinol dehydrogenase 12, protein WWC3, intraflagellar transport protein 88 homolog, superoxide dismutase [Cu-Zn], and retinal dehydrogenase 1. The network pathway was related to connective tissue disorder, developmental disorder, and hereditary disorder, with the identified proteins centered around dysregulation of ERK1/2 and F Actin signaling pathways. Cancer-associated protein alterations such as upregulation of peroxiredoxin-1, annexin 5, and iNOS, and downregulation of RDH12, retinaldehyde dehydrogenase 1, SOD1, and MYL 9, were found in the EC tissues of the diabetic group. Differential expression of proteins linked to cancer metastasis, such as the upregulation of vinculin and endoplasmin and downregulation of WWC3 and IFT88, was seen in the patients with diabetes. Calreticulin and alpha-enolase, which might have a role in the interplay between diabetes and EC, need further investigation.

Conservation of Epithelial-to-Mesenchymal Transition Process in Neural Crest Cells and Metastatic Cancer

Epithelial to mesenchymal transition (EMT) is a highly conserved cellular process in several species, from worms to humans. EMT plays a fundamental role in early embryogenesis, wound healing, and cancer metastasis. For neural crest cell (NCC) development, EMT typically results in forming a migratory and potent cell population that generates a wide variety of cell and tissue, including cartilage, bone, connective tissue, endocrine cells, neurons, and glia amongst many others. The degree of conservation between the signaling pathways that regulate EMT during development and metastatic cancer (MC) has not been fully established, despite ample studies. This systematic review and meta-analysis dissects the major signaling pathways involved in EMT of NCC development and MC to unravel the similarities and differences. While the FGF, TGFβ/BMP, SHH, and NOTCH pathways have been rigorously investigated in both systems, the EGF, IGF, HIPPO, Factor Receptor Superfamily, and their intracellular signaling cascades need to be the focus of future NCC studies. In general, meta-analyses of the associated signaling pathways show a significant number of overlapping genes (particularly ligands, transcription regulators, and targeted cadherins) involved in each signaling pathway of both systems without stratification by body segments and cancer type. Lack of stratification makes it difficult to meaningfully evaluate the intracellular downstream effectors of each signaling pathway. Finally, pediatric neuroblastoma and melanoma are NCC-derived malignancies, which emphasize the importance of uncovering the EMT events that convert NCC into treatment-resistant malignant cells.

WBP2 negatively regulates the Hippo pathway by competitively binding to WWC3 with LATS1 to promote non-small cell lung cancer progression

WW domain binding protein-2 (WBP2) can function as a Yes-associated protein/transcriptional co-activator with PDZ-binding motif (YAP/TAZ) co-activator and has a crucial role in promoting breast cancer progression. However, the expression and potential molecular mechanisms of WBP2 in the context of lung cancer are not fully understood. We determined that WBP2 was highly expressed in lung cancer specimens and cell lines and that this expression was closely related to the advanced pTNM stage, lymph node metastasis, and poor prognosis of patients. In addition, gain- and loss-of-function experiments revealed that WBP2 could significantly promote the proliferation and invasion of lung cancer cells both in vivo and in vitro. To elucidate the underlying molecular mechanism, we determined that wild-type WBP2 could competitively bind to the WW domain of WWC3 (WW and C2 domain-containing-3) with LATS1 (Large tumor suppressor-1) through its PPxY motifs, thus inhibiting the formation of the WWC3-LATS1 complex, reducing the phosphorylation level of LATS1, suppressing the activity of the Hippo pathway, and ultimately promoting YAP nuclear translocation. Therefore, from the aspect of upstream molecules of Hippo signaling, WBP2 promotes the malignant phenotype of lung cancer cells in a unique manner that is not directly dependent upon YAP, thus providing a corresponding experimental basis for the development of targeted therapeutic drugs for lung cancer.

WWC Proteins: Important Regulators of Hippo Signaling in Cancer

Simple Summary

The conserved Hippo pathway regulates cell proliferation and apoptosis via a complex interplay of transcriptional activities, post-translational protein modifications, specific protein–protein interactions and cellular transport processes. Deregulating this highly balanced system can lead to hyperproliferation, organ overgrowth and cancer. Although WWC proteins are known as components of the Hippo signaling pathway, their association with tumorigenesis is often neglected. This review aims to summarize the current knowledge on WWC proteins and their contribution to Hippo signaling in the context of cancer.

Abstract

The Hippo signaling pathway is known to regulate cell differentiation, proliferation and apoptosis. Whereas activation of the Hippo signaling pathway leads to phosphorylation and cytoplasmic retention of the transcriptional coactivator YAP, decreased Hippo signaling results in nuclear import of YAP and subsequent transcription of pro-proliferative genes. Hence, a dynamic and precise regulation of the Hippo signaling pathway is crucial for organ size control and the prevention of tumor formation. The transcriptional activity of YAP is controlled by a growing number of upstream regulators including the family of WWC proteins. WWC1, WWC2 and WWC3 represent cytosolic scaffolding proteins involved in intracellular transport processes and different signal transduction pathways. Earlier in vitro experiments demonstrated that WWC proteins positively regulate the Hippo pathway via the activation of large tumor suppressor kinases 1/2 (LATS1/2) kinases and the subsequent cytoplasmic accumulation of phosphorylated YAP. Later, reduced WWC expression and subsequent high YAP activity were shown to correlate with the progression of human cancer in different organs. Although the function of WWC proteins as upstream regulators of Hippo signaling was confirmed in various studies, their important role as tumor modulators is often overlooked. This review has been designed to provide an update on the published data linking WWC1, WWC2 and WWC3 to cancer, with a focus on Hippo pathway-dependent mechanisms.

TRIP13 promotes the proliferation and invasion of lung cancer cells via the Wnt signaling pathway and epithelial-mesenchymal transition

Thyroid hormone receptor interactor 13 (TRIP13) is an ATPase that has been found to be overexpressed in many tumors. The aim of this study was to investigate the role of TRIP13 and its mechanism of action in lung cancer. The expression of TRIP13 was examined in lung cancer tissues and corresponding normal lung tissues by western blotting. TRIP13 was overexpressed or knocked down by transient transfection or siRNA interference in lung cancer cells, respectively. The expression of key proteins associated with the Wnt signaling pathway and epithelial-mesenchymal transition (EMT) was assessed. The interaction between TRIP13 and low-density lipoprotein receptor-related protein 6 (LRP6) was examined by co-immunoprecipitation and laser confocal immunofluorescence. Moreover, this study determined the proliferative and invasive ability of cells through colony formation, cell proliferation, and Matrigel invasion assays. The expression of TRIP13 was higher in lung cancer tissues than in normal lung tissues (p = 0.002), and this correlated with poor patient prognosis (p < 0.001). In addition, overexpression of TRIP13 enhanced the levels of active β-catenin and target proteins of the Wnt signaling pathways (p < 0.05). This study found that TRIP13 can co-localize and bind with LRP6. Furthermore, overexpression of TRIP13 caused the upregulation of N-cadherin, Snail, and vimentin, and the downregulation of E-cadherin (p < 0.05). The aforementioned results were reversed after knocking down the expression of TRIP13 (p < 0.05). TRIP13 is highly expressed in lung cancers, indicating poor prognosis. overexpression of TRIP13 promotes the proliferative and invasive ability of lung cancer cells via the activation of Wnt signaling pathway and EMT.

Structural and Functional Overview of TEAD4 in Cancer Biology

TEA domain transcription factor 4 (TEAD4) is an important member of the TEAD family. As a downstream effector of the Hippo pathway, TEAD4 has essential roles in cell proliferation, cell survival, tissue regeneration, and stem cell maintenance. TEAD4 contains a TEA DNA binding domain that binds the promoters of target genes and a Yes-associated protein/transcriptional co-activator with PDZ-binding motif (YAP/TAZ) binding domain that associates with transcriptional cofactors. TEAD4 coordinates with YAP, TAZ, VGLL, and other transcription factors to regulate different cellular processes in cancer via its transcriptional output. Moreover, TEAD4 undergoes post-translational modifications and subcellular translocations, and both processes have been shown to shed new insights on how TEAD transcriptional activity can be modified. In summary, TEAD4 has important roles in cancer, including epithelial–mesenchymal transition (EMT), metastasis, cancer stem cell dynamics, and chemotherapeutic drug resistance, suggesting that TEAD4 may be a promising prognostic biomarker in cancer.

Interaction of BACH2 with FUS promotes malignant progression of glioma cells via the TSLNC8-miR-10b-5p-WWC3 pathway

Glioma, a common malignant tumour of the human central nervous system, has poor prognosis and limited treatment options. Dissecting the biological mechanisms underlying glioma pathogenesis can facilitate the development of better therapies. Here, we investigated the endogenous expression of BTB and CNC homolog 2 (BACH2), fused in sarcoma (FUS), TSLNC8 and microRNA (miR)‐10b‐5p in glioma cells and tissues. We studied the interaction between BACH2 and FUS and its contribution to glioma progression. We demonstrated that the interaction between BACH2 and FUS promoted glioma progression via transcriptional inhibition of TSLNC8. Overexpression of TSLNC8 restrained glioma progression by suppressing miR‐10b‐5p. Binding of TSLNC8 to miR‐10b‐5p attenuated the suppression of WWC family member 3 (WWC3) by miR‐10b‐5p and activated the Hippo signalling pathway. Growth of subcutaneous xenografts could be inhibited by knockdown of BACH2 or FUS, by overexpressing TSLNC8 or a combination of the three, also leading to a prolonged survival in nude mice. Our results indicate that the BACH2 and FUS/TSLNC8/miR‐10b‐5p/WWC3 axis is responsible for glioma development and could serve as a potential target for the development of new glioma therapies.

Overexpression of Nemo-like Kinase Promotes the Proliferation and Invasion of Lung Cancer Cells and Indicates Poor Prognosis

BACKGROUND

Nemo-like kinase (NLK) is an evolutionarily conserved MAP kinaserelated kinase involved in the pathogenesis of several human cancers.

OBJECTIVE

The aim of this study was to investigate the expression and role of NLK in lung cancers, and its underlying mechanisms.

METHODS

We examined the expression of NLK in lung cancer tissues through western blot analysis. We enhanced or knocked down NLK expression by gene transfection or RNA interference, respectively, in lung cancer cells, and examined expression alterations of key proteins in the Wnt signaling pathway and in epithelial-mesenchymal transition (EMT). We also examined the roles of NLK in the proliferation and invasiveness of lung cancer cells by cell proliferation, colony formation, and Matrigel invasion assays.

RESULTS

NLK expression was found to be significantly higher in lung cancer tissue samples than in corresponding healthy lung tissue samples. Overexpression of NLK correlated with poor prognosis of patients with lung cancer. Overexpression of NLK upregulated β-catenin, TCF4, and Wnt target genes such as cyclin D1, c-Myc, and MMP7. N-cadherin and TWIST, the key proteins in EMT, were upregulated, while E-cadherin expression was reduced. Additionally, proliferation, colony formation, and invasion turned out to be enhanced in NLK-overexpressing cells. After NLK knockdown in lung cancer cells, we obtained the opposite results.

CONCLUSION

NLK is overexpressed in lung cancers and indicates poor prognosis. Overexpression of NLK activates the Wnt signaling pathway and EMT and promotes the proliferation and invasiveness of lung cancer cells.

Wwc2 Is a Novel Cell Division Regulator During Preimplantation Mouse Embryo Lineage Formation and Oogenesis

Formation of the hatching mouse blastocyst marks the end of preimplantation development, whereby previous cell cleavages culminate in the formation of three distinct cell lineages (trophectoderm, primitive endoderm and epiblast). We report that dysregulated expression of Wwc2, a genetic paralog of Kibra/Wwc1 (a known activator of Hippo-signaling, a key pathway during preimplantation development), is specifically associated with cell autonomous deficits in embryo cell number and cell division abnormalities. Division phenotypes are also observed during mouse oocyte meiotic maturation, as Wwc2 dysregulation blocks progression to the stage of meiosis II metaphase (MII) arrest and is associated with spindle defects and failed Aurora-A kinase (AURKA) activation. Oocyte and embryo cell division defects, each occurring in the absence of centrosomes, are fully reversible by expression of recombinant HA-epitope tagged WWC2, restoring activated oocyte AURKA levels. Additionally, clonal embryonic dysregulation implicates Wwc2 in maintaining the pluripotent epiblast lineage. Thus, Wwc2 is a novel regulator of meiotic and early mitotic cell divisions, and mouse blastocyst cell fate.

ZEB1-Mediated Transcriptional Upregulation of circWWC3 Promotes Breast Cancer Progression through Activating Ras Signaling Pathway

Zinc finger E-box binding homeobox 1 (ZEB1) has been widely recognized as an important driver of tumor growth and metastasis. However, nothing is known about ZEB1-regulated circular (circ)RNAs in cancer. In the current study, we evaluated the function of a novel ZEB1-regulated circRNA derived from the WWC3 gene locus, circWWC3 in breast cancer progression. We found that ZEB1 upregulated circWWC3 expression but not the linear WWC3 mRNA expression. circWWC3 is highly expressed in breast cancer tissues and is associated with the poor prognosis of breast cancer patients. Silencing of circWWC3 significantly suppresses the proliferation, migration, and invasion of breast cancer cells. Mechanically, circWWC3 upregulates multiple oncogenes' expression of the Ras signaling pathway through acting as the sponge of microRNA (miR)-26b-3p and miR-660-3p. Moreover, short hairpin (sh)RNA-mediated knockdown of circWWC3 partially antagonized ZEB1-mediated breast cancer growth and metastasis in vivo. Our findings reveal that ZEB1-mediated upregulation of circWWC3 promotes breast cancer progression through activating Ras signaling pathway, which provides a potential therapeutic target and prognostic biomarker for breast cancer.

WW and C2 domain-containing protein-3 promoted EBSS-induced apoptosis through inhibiting autophagy in non-small cell lung cancer cells

Background

WW and C2 domain-containing protein-3 (WWC3) was identified in our previous studies as a tumor suppressor gene, which inhibits the proliferation and invasiveness of lung cancer cells. However, the relationship between WWC3 and autophagy and apoptosis in lung cancer cells is unclear. In this study, we aimed to investigate the potential role of WWC3 in starvation-induced autophagy and apoptosis in non-small cell lung carcinoma (NSCLC) cells.

Methods

The immunoblotting assay and quantitative real-time polymerase chain reaction (RT-qPCR) were used for observing the change of WWC3 protein and mRNA level under starvation condition. The immunoblotting assay and immunofluorescence assay were performed to detect the impact of WWC3 expression on autophagy process induced by Earle's balanced salt solution (EBSS) in lung cancer cells; APC/propidium iodide (PI) apoptosis assay, caspase-3/7 activity assay and MTT assay were used for the apoptosis and proliferation detection of lung cancer cells.

Results

After starvation had been induced with EBSS, WWC3 expression was significantly decreased in the NSCLC cells. Ectopic WWC3 expression weakened the autophagy process in a Beclin1-independent manner and promoted non-small cell lung cancer cell apoptosis via EBSS starvation. Moreover, the inhibition of WWC3 gene knockout was weakened by 3-methyladenine (3-MA), an autophagy inhibitor.

Conclusions

These results indicate that WWC3 promotes apoptosis and death of starved lung cancer cells, at least partly through autophagy.

FAM83A Promotes Lung Cancer Progression by Regulating the Wnt and Hippo Signaling Pathways and Indicates Poor Prognosis

FAM83A (family with sequence similarity 83, member A) has been found to be highly expressed in cancers. The purpose of this study was to clarify the role and mechanism of FAM83A in lung cancers. The expression of FAM83A in lung cancer cells was enhanced by gene transfection or knocked down by small interfering RNA interference. The key proteins of the Wnt signaling pathway, the Hippo signaling pathway, and epithelial–mesenchymal transition (EMT) were examined using Western blot. The proliferation and invasion of lung cancer cells were examined using cell proliferation, colony formation, and invasion assays. The expression of FAM83A in lung cancer tissues was significantly increased and was correlated with advanced tumor–node–metastasis (TNM) stage and poor prognosis. Overexpression of FAM83A enhanced the proliferation, colony formation, and invasion of lung cancer cells. Meanwhile, FAM83A overexpression increased the expression of active β-catenin and Wnt target genes and the activity of EMT. Furthermore, in FAM83A-overexpressed cells, the activity of Hippo pathway was downregulated, whereas the expression of yes-associated protein (YAP) and its downstream targets cyclin E and CTGF were upregulated. The inhibitor of the Wnt signaling pathway, XAV-939, reversed the promoting effect of FAM83A on YAP, cyclin E, and CTGF. On knocking down the expression of FAM83A, we obtained the opposite results. However, the inhibitor of GSK3β, CHIR-99021, restored the expression of YAP, cyclin E, and CTGF after FAM83A was knocked down. FAM83A is highly expressed in lung cancers and correlated with advanced TNM stage and poor prognosis. FAM83A promotes the proliferation and invasion of lung cancer cells by regulating the Wnt and Hippo signaling pathways and EMT process.

The E-Cadherin and N-Cadherin Switch in Epithelial-to-Mesenchymal Transition: Signaling, Therapeutic Implications, and Challenges

Epithelial-to-Mesenchymal Transition (EMT) has been shown to be crucial in tumorigenesis where the EMT program enhances metastasis, chemoresistance and tumor stemness. Due to its emerging role as a pivotal driver of tumorigenesis, targeting EMT is of great therapeutic interest in counteracting metastasis and chemoresistance in cancer patients. The hallmark of EMT is the upregulation of N-cadherin followed by the downregulation of E-cadherin, and this process is regulated by a complex network of signaling pathways and transcription factors. In this review, we summarized the recent understanding of the roles of E- and N-cadherins in cancer invasion and metastasis as well as the crosstalk with other signaling pathways involved in EMT. We also highlighted a few natural compounds with potential anti-EMT property and outlined the future directions in the development of novel intervention in human cancer treatments. We have reviewed 287 published papers related to this topic and identified some of the challenges faced in translating the discovery work from bench to bedside.

No excessive mutations in transcription activator-like effector nuclease-mediated α-1,3-galactosyltransferase knockout Yucatan miniature pigs

OBJECTIVE

Specific genomic sites can be recognized and permanently modified by genome editing. The discovery of endonucleases has advanced genome editing in pigs, attenuating xenograft rejection and cross-species disease transmission. However, off-target mutagenesis caused by these nucleases is a major barrier to putative clinical applications. Furthermore, off-target mutagenesis by genome editing has not yet been addressed in pigs.

METHODS

Here, we generated genetically inheritable α-1,3-galactosyltransferase (GGTA1) knockout Yucatan miniature pigs by combining transcription activator-like effector nuclease (TALEN) and nuclear transfer. For precise estimation of genomic mutations induced by TALEN in GGTA1 knockout pigs, we obtained the whole-genome sequence of the donor cells for use as an internal control genome.

RESULTS

In-depth whole-genome sequencing analysis demonstrated that TALEN-mediated GGTA1 knockout pigs had a comparable mutation rate to homologous recombination-treated pigs and wild-type strain controls. RNA sequencing analysis associated with genomic mutations revealed that TALEN-induced off-target mutations had no discernable effect on RNA transcript abundance.

CONCLUSION

Therefore, TALEN appears to be a precise and safe tool for generating genome-edited pigs, and the TALEN-mediated GGTA1 knockout Yucatan miniature pigs produced in this study can serve as a safe and effective organ and tissue resource for clinical applications.

The Hippo-YAP pathway regulates the proliferation of alveolar epithelial progenitors after acute lung injury

Regeneration of pulmonary epithelial cells plays an important role in the recovery of acute lung injury (ALI), which is defined by pulmonary epithelial cell death. However, the mechanism of the regenerative capacity of alveolar epithelial cells is unknown. Using a lung injury mouse model induced by hemorrhagic shock and lipopolysaccharide, a protein mass spectrometry-based high-throughput screening and linage tracing technology to mark alveolar epithelial type 2 cells (AEC2s), we analyzed the mechanism of alveolar epithelial cells proliferation. We demonstrated that the expression of Hippo-yes-associated protein 1 (YAP1) key proteins were highly consistent with the regularity of the proliferation of alveolar epithelial type 2 cells after ALI. Furthermore, the results showed that YAP1+ cells in lung tissue after ALI were mainly Sftpc lineage-labeled AEC2s. An in vitro proliferation assay of AEC2s demonstrated that AEC2 proliferation was significantly inhibited by both YAP1 small interfering RNA and Hippo inhibitor. These findings revealed that YAP functioned as a key regulator to promote AEC2s proliferation, with the Hippo signaling pathway playing a pivotal role in this process.

FRMPD1 activates the Hippo pathway via interaction with WWC3 to suppress the proliferation and invasiveness of lung cancer cells

Purpose: The expression of FERM-domain-containing protein-1 (FRMPD1)/FERM and PDZ domain-containing protein-2 (FRMD2) in malignant tumors, including lung cancer, and its underlying molecular mechanism have not been reported yet. Materials and methods: Immunohistochemistry was performed to analyze the expression of FRMPD1 in lung cancer tissues, and statistical analysis was applied to analyze the relationship between FRMPD1 expression and clinicopathological factors. The biological effects of FRMPD1 on lung cancer cell proliferation and invasion were determined by functional experiments both in vivo and in vitro. Immunoblotting, RT-qPCR, dual-luciferase assay, and immunofluorescence were performed to demonstrate whether FRMPD1 stimulates Hippo signaling. Co-immunoprecipitation assays were used to clarify the underlying role of FRMPD1 in Hippo pathway activation via interaction with WW and C2 domain containing protein-3 (WWC3). Results: We found that FRMPD1 expression in lung cancer specimens was lower than that in normal bronchial epithelium and normal submucosal glands. FRMPD1 expression had a negative correlation with age, Tumor-Node-Metastasis (TNM) stage, lymph node metastasis, as well as poor prognosis. Moreover, ectopic expression of FRMPD1 significantly inhibited the proliferation and invasion of lung cancer cells, and inhibition of FRMPD1 expression led to opposite effects. Mechanistically, we found that FRMPD1 interacted with the C-terminal PDZ binding motif of WWC3 via its PSD95/DLG/ZO1 (PDZ) domain and promoted the phosphorylation of large tumor suppressor-1 (LATS1), thus inhibiting the nuclear translocation of yes-associated protein (YAP). Conclusion: FRMPD1 could activate the Hippo pathway and ultimately inhibit the malignant behavior of lung cancer cells through its interaction with WWC3. This work will provide an important experimental basis for the discovery of novel biomarkers of lung cancer and the development of targeted drugs.

Loss of KIBRA function activates EGFR signaling by inducing AREG

The Hippo signaling pathway is a central regulator of organ size, tissue homeostasis, and tumorigenesis. KIBRA is a member of the WW domain-containing protein family and has recently been reported to be an upstream protein in the Hippo signaling pathway. However, the clinical significance of KIBRA deregulation and the underlying mechanisms by which KIBRA regulates breast cancer (BC) initiation and progression remain poorly understood. Here, we report that KIBRA knockdown in mammary epithelial cells induced epithelial-to-mesenchymal transition (EMT) and increased cell migration and tumorigenic potential. Mechanistically, we observed that inhibiting KIBRA induced growth factor-independent cell proliferation in 2D and 3D culture due to the secretion of amphiregulin (AREG), an epidermal growth factor receptor (EGFR) ligand. Also, we show that AREG activation in KIBRA-knockdown cells depended on the transcriptional coactivator YAP1. Significantly, decreased expression of KIBRA is correlated with recurrence and reduced BC patient survival. In summary, this study elucidates the molecular events that underpin the role of KIBRA in BC. As a result, our work provides biological insight into the role of KIBRA as a critical regulator of YAP1-mediated oncogenic growth, and may have clinical potential for facilitating patient stratification and identifying novel therapeutic approaches for BC patients.