Medical Sciences Commons^™

Microrna-1 Attenuates The Growth And Metastasis Of Small Cell Lung Cancer Through Cxcr4/Foxm1/Rrm2 Axis, Parvez Khan, Jawed A. Siddiqui, Prakash Kshirsagar Dr., Ramakanth Chirravuri Venkata, Shailendra K. Maurya, Tamara Mirzapoiazova, Naveenkumar Perumal, Sanjib Chaudhary, Ranjana K. Kanchan, Mahek Fatima, Md Arafat Khan, Asad Ur Rehman, Imayavaramban Lakshmanan, Sidharth Mahapatra, Geoffrey A. Talmon, Prakash Kulkarni, Apar Kishor Ganti, Maneesh Jain, Ravi Salgia, Surinder K. Batra, Mohd W. Nasser

Journal Articles: Biochemistry & Molecular Biology

BACKGROUND: Small cell lung cancer (SCLC) is an aggressive lung cancer subtype that is associated with high recurrence and poor prognosis. Due to lack of potential drug targets, SCLC patients have few therapeutic options. MicroRNAs (miRNAs) provide an interesting repertoire of therapeutic molecules; however, the identification of miRNAs regulating SCLC growth and metastasis and their precise regulatory mechanisms are not well understood.

METHODS: To identify novel miRNAs regulating SCLC, we performed miRNA-sequencing from donor/patient serum samples and analyzed the bulk RNA-sequencing data from the tumors of SCLC patients. Further, we developed a nanotechnology-based, highly sensitive method to detect microRNA-1 (miR-1, …

Gpcrs And Fibroblast Heterogeneity In Fibroblast-Associated Diseases, Nidhi V. Dwivedi, Souvik Datta, Karim El-Kersh, Ruxana Sadikot Md, Mrcp, Apar Kishor Ganti, Surinder K. Batra, Maneesh Jain

Journal Articles: Biochemistry & Molecular Biology

G protein-coupled receptors (GPCRs) are the largest and most diverse class of signaling receptors. GPCRs regulate many functions in the human body and have earned the title of "most targeted receptors". About one-third of the commercially available drugs for various diseases target the GPCRs. Fibroblasts lay the architectural skeleton of the body, and play a key role in supporting the growth, maintenance, and repair of almost all tissues by responding to the cellular cues via diverse and intricate GPCR signaling pathways. This review discusses the dynamic architecture of the GPCRs and their intertwined signaling in pathological conditions such as idiopathic …

The Tumor Suppressor Tere1 (Ubiad1) Prenyltransferase Regulates The Elevated Cholesterol Phenotype In Castration Resistant Prostate Cancer By Controlling A Program Of Ligand Dependent Sxr Target Genes., William J. Fredericks, Jorge Sepulveda, Priti Lai, John E. Tomaszewski, Ming-Fong Lin, Terry Mcgarvey, Frank J. Rauscher, S. Bruce Malkowicz

Journal Articles: Biochemistry & Molecular Biology

Castrate-Resistant Prostate Cancer (CRPC) is characterized by persistent androgen receptor-driven tumor growth in the apparent absence of systemic androgens. Current evidence suggests that CRPC cells can produce their own androgens from endogenous sterol precursors that act in an intracrine manner to stimulate tumor growth. The mechanisms by which CRPC cells become steroidogenic during tumor progression are not well defined. Herein we describe a novel link between the elevated cholesterol phenotype of CRPC and the TERE1 tumor suppressor protein, a prenyltransferase that synthesizes vitamin K-2, which is a potent endogenous ligand for the SXR nuclear hormone receptor. We show that 50% …

Androgens Upregulate Cdc25c Protein By Inhibiting Its Proteasomal And Lysosomal Degradation Pathways., Yu-Wei Chou, Li Zhang, Sakthivel Muniyan, Humera Ahmad, Satyendra Kumar, Syed Mahfuzul Alam, Ming-Fong Lin

Journal Articles: Biochemistry & Molecular Biology

Cdc25C is a cell cycle protein of the dual specificity phosphatase family essential for activating the cdk1/Cyclin B1 complex in cells entering into mitosis. Since altered cell cycle is a hallmark of human cancers, we investigated androgen regulation of Cdc25C protein in human prostate cancer (PCa) cells, including androgen-sensitive (AS) LNCaP C-33 cells and androgen-independent (AI) LNCaP C-81 as well as PC-3 cells. In the regular culture condition containing fetal bovine serum (FBS), Cdc25C protein levels were similar in these PCa cells. In a steroid-reduced condition, Cdc25C protein was greatly decreased in AS C-33 cells but not AI C-81 or …

Nicotine, Ifn-Γ And Retinoic Acid Mediated Induction Of Muc4 In Pancreatic Cancer Requires E2f1 And Stat-1 Transcription Factors And Utilize Different Signaling Cascades., Sateesh Kunigal, Moorthy P. Ponnusamy, Navneet Momi, Surinder K. Batra, Srikumar P. Chellappan

Journal Articles: Biochemistry & Molecular Biology

BACKGROUND: The membrane-bound mucins are thought to play an important biological role in cell-cell and cell-matrix interactions, in cell signaling and in modulating biological properties of cancer cell. MUC4, a transmembrane mucin is overexpressed in pancreatic tumors, while remaining undetectable in the normal pancreas, thus indicating a potential role in pancreatic cancer pathogenesis. The molecular mechanisms involved in the regulation of MUC4 gene are not yet fully understood. Smoking is strongly correlated with pancreatic cancer and in the present study; we elucidate the molecular mechanisms by which nicotine as well as agents like retinoic acid (RA) and interferon-γ (IFN-γ) induce …

Mir-25 Targets Tnf-Related Apoptosis Inducing Ligand (Trail) Death Receptor-4 And Promotes Apoptosis Resistance In Cholangiocarcinoma., Nataliya Razumilava, Steve F. Bronk, Rory L. Smoot, Christian D. Fingas, Nathan W. Werneburg, Lewis R. Roberts, Justin L. Mott

Journal Articles: Biochemistry & Molecular Biology

It has been established that microRNA expression and function contribute to phenotypic features of malignant cells, including resistance to apoptosis. Although targets and functional roles for a number of microRNAs have been described in cholangiocarcinoma, many additional microRNAs dysregulated in this tumor have not been assigned functional roles. In this study, we identify elevated miR-25 expression in malignant cholangiocarcinoma cell lines as well as patient samples. In cultured cells, treatment with the Smoothened inhibitor, cyclopamine, reduced miR-25 expression, suggesting Hedgehog signaling stimulates miR-25 production. Functionally, miR-25 was shown to protect cells against TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. Correspondingly, antagonism of …

The Raf/Mek/Extracellular Signal-Regulated Kinase 1/2 Pathway Can Mediate Growth Inhibitory And Differentiation Signaling Via Androgen Receptor Downregulation In Prostate Cancer Cells., Seung-Keun Hong, Jin-Hwan Kim, Ming-Fong Lin, Jong-In Park

Journal Articles: Biochemistry & Molecular Biology

Upregulated ERK1/2 activity is correlated with androgen receptor (AR) downregulation in certain prostate cancer (PCa) that exhibits androgen deprivation-induced neuroendocrine differentiation, but its functional relevance requires elucidation. We found that sustained ERK1/2 activation using active Raf or MEK1/2 mutants is sufficient to induce AR downregulation at mRNA and protein levels in LNCaP. Downregulation of AR protein, but not mRNA, was blocked by proteasome inhibitors, MG132 and bortezomib, indicating that the pathway regulation is mediated at multiple points. Ectopic expression of a constitutively active AR inhibited Raf/MEK/ERK-mediated regulation of the differentiation markers, neuron-specific enolase and neutral endopeptidase, and the cyclin-dependent kinase …

Steroids Up-Regulate P66shc Longevity Protein In Growth Regulation By Inhibiting Its Ubiquitination., Santosh Kumar, Satyendra Kumar, Mythilypriya Rajendran, Syed Mahfuzul Alam, Fen-Fen Lin, Pi-Wan Cheng, Ming-Fong Lin

Journal Articles: Biochemistry & Molecular Biology

BACKGROUND: p66Shc, an isoform of Shc adaptor proteins, mediates diverse signals, including cellular stress and mouse longevity. p66Shc protein level is elevated in several carcinomas and steroid-treated human cancer cells. Several lines of evidence indicate that p66Shc plays a critical role in steroid-related carcinogenesis, and steroids play a role in its elevated levels in those cells without known mechanism.

METHODS AND FINDINGS: In this study, we investigated the molecular mechanism by which steroid hormones up-regulate p66Shc protein level. In steroid-treated human prostate and ovarian cancer cells, p66Shc protein levels were elevated, correlating with increased cell proliferation. These steroid effects on …

Death Receptor 5 Internalization Is Required For Lysosomal Permeabilization By Trail In Malignant Liver Cell Lines., Yuko Akazawa, Justin L. Mott, Steven F. Bronk, Nathan W. Werneburg, Alisan Kahraman, Maria Eugenia Guicciardi, Xue Wei Meng, Shigeru Kohno, Vijay H. Shah, Scott H. Kaufmann, Mark A. Mcniven, Gregory J. Gores

Journal Articles: Biochemistry & Molecular Biology

BACKGROUND & AIMS: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) cytotoxicity in hepatocellular carcinoma cells is mediated by lysosomal permeabilization. Our aims were to determine which TRAIL receptor, death receptor (DR) 4 or DR5, mediates lysosomal permeabilization and assess whether receptor endocytosis followed by trafficking to lysosomes contributes in this process.

METHODS: TRAIL ligand internalization in Huh-7 cells was examined by confocal microscopy using Flag-tagged TRAIL, whereas DR4- and DR5-enhanced green fluorescent protein internalization was assessed by total internal reflection microscopy. Clathrin-dependent endocytosis was inhibited by expressing dominant negative dynamin.

RESULTS: Although Huh-7 cells express both TRAIL receptors, short hairpin RNA …

Upregulation Of Pip3-Dependent Rac Exchanger 1 (P-Rex1) Promotes Prostate Cancer Metastasis., Jianbing Qin, Yan Xie, Bo Wang, Mikio Hoshino, Dennis W. Wolff, Jing Zhao, Margaret A. Scofield, Frank J. Dowd, Ming-Fong Lin, Yaping Tu

Journal Articles: Biochemistry & Molecular Biology

Excessive activation of G-protein-coupled receptor (GPCR) and receptor tyrosine kinase (RTK) pathways has been linked to prostate cancer metastasis. Rac activation by guanine nucleotide exchange factors (GEFs) plays an important role in directional cell migration, a critical step of tumor metastasis cascades. We found that the upregulation of P-Rex1, a Rac-selective GEF synergistically activated by Gbetagamma freed during GPCR signaling, and PIP3, generated during either RTK or GPCR signaling, strongly correlates with metastatic phenotypes in both prostate cancer cell lines and human prostate cancer specimens. Silencing endogenous P-Rex1 in metastatic prostate cancer PC-3 cells selectively inhibited Rac activity and reduced …

The Notch Regulator Maml1 Interacts With P53 And Functions As A Coactivator., Yongtong Zhao, Rebecca B. Katzman, Laurie M. Delmolino, Ishfaq Bhat, Ying Zhang, Channabasavaiah B. Gurumurthy, Aleksandra Germaniuk-Kurowska, Honey V. Reddi, Aharon Solomon, Mu-Sheng Zeng, Aisha Kung, Hui Ma, Qingshen Gao, Goberdhan Dimri, Adina Stanculescu, Lucio Miele, Lizi Wu, James D. Griffin, David E. Wazer, Hamid Band, Vimla Band

Journal Articles: Biochemistry & Molecular Biology

Members of the evolutionarily conserved Mastermind (MAM) protein family, including the three related mammalian Mastermind-like (MAML) proteins MAML1-3, function as crucial coactivators of Notch-mediated transcriptional activation. Given the recent evidence of cross-talk between the p53 and Notch signal transduction pathways, we have investigated whether MAML1 may also be a transcriptional coactivator of p53. Indeed, we show here that MAML1 is able to interact with p53. We show that MAML1-p53 interaction involves the N-terminal region of MAML1 and the DNA-binding domain of p53, and we use a chromatin immunoprecipitation assay to show that MAML1 is part of the activator complex that …

Androgen-Regulated Formation And Degradation Of Gap Junctions In Androgen-Responsive Human Prostate Cancer Cells., Shalini Mitra, Lakshmanan Annamalai, Souvik Chakraborty, Kristen E. Johnson, Xiao-Hong Song, Surinder K. Batra, Parmender P. Mehta

Journal Articles: Biochemistry & Molecular Biology

The constituent proteins of gap junctions, called connexins (Cxs), have a short half-life. Despite this, the physiological stimuli that control the assembly of Cxs into gap junctions and their degradation have remained poorly understood. We show here that in androgen-responsive human prostate cancer cells, androgens control the expression level of Cx32-and hence the extent of gap junction formation-post-translationally. In the absence of androgens, a major fraction of Cx32 is degraded presumably by endoplasmic reticulum-associated degradation, whereas in their presence, this fraction is rescued from degradation. We also show that Cx32 and Cx43 degrade by a similar mechanism. Thus, androgens regulate …