Dataset Information

Prolactin-induced protein is required for cell cycle progression in breast cancer.

ABSTRACT: Prolactin-induced protein (PIP) is expressed in the majority of breast cancers and is used for the diagnostic evaluation of this disease as a characteristic biomarker; however, the molecular mechanisms of PIP function in breast cancer have remained largely unknown. In this study, we carried out a comprehensive investigation of PIP function using PIP silencing in a broad group of breast cancer cell lines, analysis of expression microarray data, proteomic analysis using mass spectrometry, and biomarker studies on breast tumors. We demonstrated that PIP is required for the progression through G1 phase, mitosis, and cytokinesis in luminal A, luminal B, and molecular apocrine breast cancer cells. In addition, PIP expression is associated with a transcriptional signature enriched with cell cycle genes and regulates key genes in this process including cyclin D1, cyclin B1, BUB1, and forkhead box M1 (FOXM1). It is notable that defects in mitotic transition and cytokinesis following PIP silencing are accompanied by an increase in aneuploidy of breast cancer cells. Importantly, we have identified novel PIP-binding partners in breast cancer and shown that PIP binds to ?-tubulin and is necessary for microtubule polymerization. Furthermore, PIP interacts with actin-binding proteins including Arp2/3 and is needed for inside-out activation of integrin-?1 mediated through talin. This study suggests that PIP is required for cell cycle progression in breast cancer and provides a rationale for exploring PIP inhibition as a therapeutic approach in breast cancer that can potentially target microtubule polymerization.

SUBMITTER: Naderi A

PROVIDER: S-EPMC4094838 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Prolactin-induced protein is required for cell cycle progression in breast cancer.

Naderi Ali A Vanneste Marion M

Neoplasia (New York, N.Y.) 20140401 4

Prolactin-induced protein (PIP) is expressed in the majority of breast cancers and is used for the diagnostic evaluation of this disease as a characteristic biomarker; however, the molecular mechanisms of PIP function in breast cancer have remained largely unknown. In this study, we carried out a comprehensive investigation of PIP function using PIP silencing in a broad group of breast cancer cell lines, analysis of expression microarray data, proteomic analysis using mass spectrometry, and biom ...[more]

PMID: 24862759

Similar Datasets

Project description:Prolactin-induced protein (PIP) is a small secreted glycoprotein carrying several N-linked carbohydrate chains. The expression of PIP is generally restricted to cells with apocrine properties. It was found in apocrine glands of the axilla, vulva, eyelid, ear canal, and seminal vesicle. Being a secretory protein, PIP is present in seminal plasma, saliva, lacrimal fluid, tears, sweat gland secretion. Little is known about the biological role of PIP. It binds to numerous proteins, however, in most cases the biological role of such interactions is poorly understood. A notable exception is its binding to CD4 receptors present on the surface of T lymphocytes, macrophages, and spermatozoa. The available data suggest that PIP can have immunomodulatory functions and plays an important role in cell-mediate adoptive immunity. PIP binds to bacteria from several genera, which suggests that this glycoprotein may participate also in innate immunity and protection of hosts against microbial infections. Increased levels of PIP were found in several types of human cancer (prostate, sweat and salivary gland cancers). It is especially common in breast cancer, however, data on the expression of PIP in normal and cancerous breast cancer tissues are to some degree conflicting. In early studies, it was shown that PIP is absent or its expression is very low in normal breast epithelium, whereas in breast cancers PIP is frequently expressed and present in large amounts. On the other hand, later study showed that expression of PIP is lower in advanced apocrine carcinomas and invasive carcinomas than in, respectively, in situ carcinomas and adjacent normal tissue. The most recent study revealed that PIP gene expression decreased gradually along with higher stage and grade of breast cancer. In agreement with these data, it was shown that that low levels or the lack of PIP expression are associated with a worse response of breast cancer cells to chemotherapy. It was proposed that PIP plays important role in the development and progression of breast cancer. However, its role in these processes is both unclear and controversial. In this review, the role of PIP in both physiological processes and carcinogenesis is discussed.

Project description:Molecular apocrine is a subtype of estrogen receptor (ER)-negative breast cancer that is characterized by a steroid-response gene signature. We have recently identified a positive feedback loop between androgen receptor (AR) and extracellular signal-regulated kinase (ERK) signaling in this subtype. In this study, we investigated the transcriptional regulation of molecular apocrine genes by the AR-ERK feedback loop.The transcriptional effects of AR and ERK inhibition on molecular apocrine genes were assessed in cell lines. The most regulated gene in this process, prolactin-induced protein (PIP), was further studied using immunohistochemistry of breast tumors and xenograft models. The transcriptional regulation of PIP was assessed by luciferase reporter assay and chromatin immunoprecipitation. The functional significance of PIP in cell invasion and viability was assessed using siRNA knockdown experiments and the mechanism of PIP effect on integrin-?1 signaling was studied using immunoblotting and immunoprecipitation.We found that PIP is the most regulated molecular apocrine gene by the AR-ERK feedback loop and is overexpressed in ER-/AR+ breast tumors. In addition, PIP expression is regulated by AR-ERK signaling in xenograft models. These observations are explained by the fact that PIP is a target gene of the ERK-CREB1 pathway and is also induced by AR activation. Furthermore, we demonstrated that PIP has a significant functional role in maintaining cell invasion and viability of molecular apocrine cells because of a positive regulatory effect on the Integrin-ERK and Integrin-Akt signaling pathways. In fact, PIP-knockdown markedly decreases the phosphorylation of ERK, Akt, and CREB1. Importantly, PIP knockdown leads to a marked reduction of integrin-?1 binding to ILK1 and ErbB2 that can be reversed by the addition of fibronectin fragments.We have identified a novel feedback loop between PIP and CREB1 mediated through the Integrin signaling pathway. In this process, PIP cleaves fibronectin to release fragments that activate integrin signaling, which in turn increases PIP expression through the ERK-CREB1 pathway. In addition, we demonstrated that PIP expression has a profound effect on cell invasion and the viability of molecular apocrine cells. Therefore, PIP signaling may be a potential therapeutic target in molecular apocrine breast cancer.

Project description:BackgroundHistone deacetylases (HDACs) engage in the regulation of various cellular processes by controlling global gene expression. The dysregulation of HDACs leads to carcinogenesis, making HDACs ideal targets for cancer therapy. However, the use of HDAC inhibitors (HDACi) as single agents has been shown to have limited success in treating solid tumors in clinical studies. This study aimed to identify a novel downstream effector of HDACs to provide a potential target for combination therapy.MethodsTranscriptome sequencing and bioinformatics analysis were performed to screen for genes responsive to HDACi in breast cancer cells. The effects of HDACi on cell viability were detected using the MTT assay. The mRNA and protein levels of genes were determined by quantitative reverse transcription-PCR (qRT-PCR) and Western blotting. Cell cycle distribution and apoptosis were analyzed by flow cytometry. The binding of CREB1 (cAMP-response element binding protein 1) to the promoter of the KDELR (The KDEL (Lys-Asp-Glu-Leu) receptor) gene was validated by the ChIP (chromatin immunoprecipitation assay). The association between KDELR2 and protein of centriole 5 (POC5) was detected by immunoprecipitation. A breast cancer-bearing mouse model was employed to analyze the effect of the HDAC3-KDELR2 axis on tumor growth.ResultsKDELR2 was identified as a novel target of HDAC3, and its aberrant expression indicated the poor prognosis of breast cancer patients. We found a strong correlation between the protein expression patterns of HADC3 and KDELR2 in tumor tissues from breast cancer patients. The results of the ChIP assay and qRT-PCR analysis validated that HDAC3 transactivated KDELR2 via CREB1. The HDAC3-KDELR2 axis accelerated the cell cycle progression of cancer cells by protecting the centrosomal protein POC5 from proteasomal degradation. Moreover, the HDAC3-KDELR2 axis promoted breast cancer cell proliferation and tumorigenesis in vitro and in vivo.ConclusionOur results uncovered a previously unappreciated function of KDELR2 in tumorigenesis, linking a critical Golgi-the endoplasmic reticulum traffic transport protein to HDAC-controlled cell cycle progression on the path of cancer development and thus revealing a potential therapeutical target for breast cancer.

Dataset Information

Prolactin-induced protein is required for cell cycle progression in breast cancer.

Publications

Prolactin-induced protein is required for cell cycle progression in breast cancer.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets