Kindlin-2, an integrin-interacting protein, regulates breast cancer progression. However, currently, no animal model to study the role of Kindlin-2 in the carcinogenesis of mammary gland is available. We established a Kindlin-2 transgenic mouse model using a mammary gland-specific promoter, mammary tumor virus(MMTV) long terminal repeat(LTR). Kindlin-2 was overexpressed in the epithelial cells of the transgenic mice. The mammary gland ductal trees were found to grow faster in MMTV-Kindlin-2 transgenic mice than in control mice during puberty. Kindlin-2 promoted mammary gland growth as indicated by more numerous duct branches and larger lumens, and more alveoli were formed in the mammary glands during pregnancy under Kindlin-2 overexpression. Importantly, mammary gland-specific expression of Kindlin-2 induced tumor formation at the age of 55 weeks on average. Additionally, the levels of estrogen receptor and progesterone receptor were decreased, whereas human epidermal growth factor receptor 2 and β-catenin were upregulated in the Kindlin-2-induced mammary tumors. These findings demonstrated that Kindlin-2 induces mammary tumor formation via activation of the Wnt signaling pathway.
目的:探讨Kindlin-2对小鼠子宫发育及雌鼠生育能力的影响及其作用机制。方法:利用Cdh16-Cre工具鼠和Kindlin-2^(flox/flox)小鼠构建在子宫内膜中特异性敲除Kindlin-2的小鼠模型,观察敲除Kindlin-2对雌鼠子宫内膜发育和生殖力的影响。在子宫内膜癌细胞系HEC-1和Ish中分别进行高表达和敲低Kindlin-2的实验,检测雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)信号通路的激活变化,并且提取特异性敲除Kindlin-2的雌鼠(实验组,基因型为Cdh16-Cre;Kindlin-2^(flox/flox))和未特异性敲除Kindlin-2的雌鼠(对照组,基因型为Kindlin-2^(flox/flox))子宫蛋白,每组包含6~8只小鼠,重复3次独立实验,检测mTOR信号通路和Hippo信号通路关键分子的蛋白水平。结果:成功构建了子宫内膜特异性敲除Kindlin-2的小鼠模型,通过鼠尾聚合酶链式反应(polymerase chain reaction,PCR)、Western blot、免疫组织化学染色(immunohistochemistry,IHC)等方法鉴定和验证Kindlin-2在小鼠子宫中的敲除效率。子宫内膜特异性敲除Kindlin-2的雌鼠与对照组相比体质量减轻、生殖能力严重受损、出生仔鼠数量减少,但出生仔鼠中雌鼠和雄鼠的比例未发生改变,通过苏木精-伊红染色实验观察表明实验组子宫内膜发育不完整、子宫壁厚度变薄。机制方面,子宫内膜癌细胞系HEC-1和Ish中敲除Kindlin-2能够下调mTOR、磷酸化mTOR、腺嘌呤核糖核苷酸激活蛋白激酶(adenosine monophosphate-activated protein kinase,AMPK)、磷酸化的AMPK和磷酸化的核糖体蛋白(ribosomal protein S6,S6)的蛋白水平,在雌鼠子宫中发现特异性敲除Kindlin-2能够上调Mps结合1(Mps one binding 1,MOB1)、磷酸化的Yes相关蛋白(Yes-associated protein,YAP)的蛋白水平。结论:Kindlin-2通过抑制mTOR信号通路、激活Hippo信号通路抑制子宫内膜的发育,进而抑制雌鼠的生育能力。
Kindlin-2, a member of the Kindlin family focal adhesion proteins, plays an important role in cardiac development. It is known that defects in the Z-disc proteins lead to hypertrophic cardiomyopathy(HCM) or dilated cardiomyopathy(DCM). Our previous investigation showed that Kindlin-2 is mainly localized at the Z-disc and depletion of Kindlin-2 disrupts the structure of the Z-Disc. Here, we reported that depletion of Kindlin-2 leads to the disordered myocardial fibers, fractured and vacuolar degeneration in myocardial fibers. Interestingly, depletion of Kindlin-2 in mice induced cardiac myocyte hypertrophy and increased the heart weight. Furthermore, decreased expression of Kindlin-2 led to cardiac dysfunction and also markedly impairs systolic function. Our data indicated that Kindlin-2 not only maintains the cardiac structure but also is required for cardiac function.
Pancreatic ductal adenocarcinoma(PDAC)is the ninth most common human malignancy and the sixth leading cause of cancer-related death in China.AcK27-HOXB9 is a newly identified HOXB9 post-transcriptional modification that can predict the outcome in lung adenocarcinoma and colon cancer well.However,the role of AcK27-HOXB9 in PDAC is unclear.The present study aims to investigate the differential diagnostic role of patients with AcK27-HOXB9 PDAC.Tissue microarrays consisting of 162 pancreatic tumor tissue samples from patients with PDAC and paired normal subjects were used to examine HOXB9 and AcK27-HOXB9 levels and localizations by immunohistochemical analysis and Western blot assay,respectively.HOXB9 was upregulated(P<0.0001),and AcK27-HOXB9(P=0.0023)was downregulated in patients with PDAC.HOXB9 promoted(P=0.0115),while AcK27-HOXB9(P=0.0279)inhibited PDAC progression.AcK27-HOXB9 predicted favorable outcome in patients with PDAC(P=0.0412).AcK27-HOXB9 also suppressed PDAC cell migration in a cell migration assay.The results of this study showed that HOXB9 promoted and AcK27-HOXB9 suppressed PDAC progression.The determination of ratio between HOXB9 and AcK27-HOXB9 exhibited potential diagnostic value in patients with PDAC.
Esophageal cancer(EC) is one of the most lethal malignancies in China, but the etiology and risk factors remain unclear.The integrin-interacting proteins Kindlin-1 and Kindlin-2 are focal adhesion molecules that activate transmembrane receptor integrins and regulate tumor cell growth, invasion, and metastasis. Here, we report that Kindlin-I and Kindlin-2 are differentially expressed among Chinese EC patients. For this, Kindlin-1 and Kindlin-2 expression was evaluated in 220 EC patients by immunohistochemistry(IHC) and found to be correlated with the EC progression, along with a variety of epidemiologic parameters,including smoking,family EC history,and EC invasion status. Moreover,data downloaded from the Oncomine database revealed that both Kindlin-1 and Kindlin-2 were upregulated in ECs compared with normal esophageal tissues; although Kindlin-1 was highly expressed in well-differentiated tumors, whereas Kindlin-2 was more prevalent in poorly differentiated tumors. Collectively, these data suggest that Kindlin-1 may inhibit, while Kindlin-2 may promote, EC progression. This study,for the first time, linked the expression of Kindlin-1 and Kindlin-2 with EC family genetic background and living habits, which may help further our understanding of the various causes of EC.
Large tumor suppressor 1(LATS1)is the key kinase controlling activation of Hippo signalling pathway.Post-translational modifications of LATS1 modulate its kinase activity.However,detailed mechanism underlying LATS1 stability and activation remains elusive.Here we report that LATS1 is acetylated by acetyltransferase CBP at K751 and is deacetylated by deacetylases SIRT3 and SIRT4.Acetylation at K751 stabilized LATS1 by decreasing LATS1 ubiquitination and inhibited LATS1 activation by reducing its phosphorylation.Mechanistically,LATS1 acetylation resulted in inhibition of YAP phosphorylation and degradation,leading to increased YAP nucleus translocation and promoted target gene expression.Functionally,LATS1-K751 Q,the acetylation mimic mutant potentiated lung cancer cell migration,invasion and tumor growth,whereas LATS1-K751 R,the acetylation deficient mutant inhibited these functions.Taken together,we demonstrated a previously unidentified post-translational modification of LATS1 that converts LATS1 from a tumor suppressor to a tumor promoter by suppression of Hippo signalling through acetylation of LATS1.
Mutations of integrin-interacting protein Kindlin-1 cause Kindler syndrome and deregulation of Kindlin-1 is implicated in human cancers. The Kindlin-1-related diseases are confined in limited tissue types. However, Kindlin-1 tissue distribution and the dogma that governs Kindlin-1 expression in normal human body are elusive. This study examined Kindlin-1 expression in normal human adult organs, human and mouse embryonic organs by immunohistochemical analyses. We identified a general principle that the level of Kindlin-1 expression in tissues is tightly correlated with the corresponding germ layers from which these tissues originate. We compared the expression of Kindlin-1 with Kindlin-2 and found that Kindlin-1 is highly expressed in epithelial tissues derived from ectoderm and endoderm, whereas Kindlin-2 is mainly expressed in mesoderm-derived tissues. Likewise, Kindlin-1 was also found highly expressed in endoderm/ectoderm-derived tissues in human and mouse embryos. Our findings indicate that Kindlin-1 may play an importance role in the development of endoderm/ectoderm related tissues.
