Medicine and Health Sciences Commons^™

Impaired Expression Of Protein Phosphatase 2a Subunits Enhances Metastatic Potential Of Human Prostate Cancer Cells Through Activation Of Akt Pathway., P Pandey, Parthasarathy Seshacharyulu, Srustidhar Das, Satyanarayana Rachagani, Moorthy P. Ponnusamy, Y Yan, Sonny L. Johansson, K Datta, Ming-Fong Lin, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

BACKGROUND: Protein phosphatase 2A (PP2A) is a dephosphorylating enzyme, loss of which can contribute to prostate cancer (PCa) pathogenesis. The aim of this study was to analyse the transcriptional and translational expression patterns of individual subunits of the PP2A holoenzyme during PCa progression.

METHODS: Immunohistochemistry (IHC), western blot, and real-time PCR was performed on androgen-dependent (AD) and androgen-independent (AI) PCa cells, and benign and malignant prostate tissues for all the three PP2A (scaffold, regulatory, and catalytic) subunits. Mechanistic and functional studies were performed using various biochemical and cellular techniques.

RESULTS: Through immunohistochemical analysis we observed significantly reduced levels of PP2A-A …

Marked Improvement Of Cytotoxic Effects Induced By Docetaxel On Highly Metastatic And Androgen-Independent Prostate Cancer Cells By Downregulating Macrophage Inhibitory Cytokine-1., M Mimeault, Sonny L. Johansson, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

BACKGROUND: Overexpression of macrophage inhibitory cytokine-1 (MIC-1) frequently occurs during the progression of prostate cancer (PC) to androgen-independent (AI) and metastatic disease states and is associated with a poor outcome of patients.

METHODS: The gain- and loss-of-function analyses of MIC-1 were performed to establish its implications for aggressive and chemoresistant phenotypes of metastatic and AI PC cells and the benefit of its downregulation for reversing docetaxel resistance.

RESULTS: The results have indicated that an enhanced level of secreted MIC-1 protein in PC3 cells is associated with their acquisition of epithelial-mesenchymal transition features and higher invasive capacity and docetaxel resistance. Importantly, …

Muc4 Overexpression Augments Cell Migration And Metastasis Through Egfr Family Proteins In Triple Negative Breast Cancer Cells., Partha Mukhopadhyay, Imayavaramban Lakshmanan, Moorthy P. Ponnusamy, Subhankar Chakraborty, Maneesh Jain, Priya Pai, Lynette M. Smith, Subodh M. Lele, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

INTRODUCTION: Current studies indicate that triple negative breast cancer (TNBC), an aggressive breast cancer subtype, is associated with poor prognosis and an early pattern of metastasis. Emerging evidence suggests that MUC4 mucin is associated with metastasis of various cancers, including breast cancer. However, the functional role of MUC4 remains unclear in breast cancers, especially in TNBCs.

METHOD: In the present study, we investigated the functional and mechanistic roles of MUC4 in potentiating pathogenic signals including EGFR family proteins to promote TNBC aggressiveness using in vitro and in vivo studies. Further, we studied the expression of MUC4 in invasive TNBC tissue …

Hypoxia-Inducing Factors As Master Regulators Of Stemness Properties And Altered Metabolism Of Cancer- And Metastasis-Initiating Cells., Murielle Mimeault, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

Accumulating lines of experimental evidence have revealed that hypoxia-inducible factors, HIF-1α and HIF-2α, are key regulators of the adaptation of cancer- and metastasis-initiating cells and their differentiated progenies to oxygen and nutrient deprivation during cancer progression under normoxic and hypoxic conditions. Particularly, the sustained stimulation of epidermal growth factor receptor (EGFR), insulin-like growth factor-1 receptor (IGF-1R), stem cell factor (SCF) receptor KIT, transforming growth factor-β receptors (TGF-βRs) and Notch and their downstream signalling elements such as phosphatidylinositol 3'-kinase (PI3K)/Akt/molecular target of rapamycin (mTOR) may lead to an enhanced activity of HIFs. Moreover, the up-regulation of HIFs in cancer cells may …

Pathobiological Implications Of Muc16 Expression In Pancreatic Cancer., Dhanya Haridas, Subhankar Chakraborty, Moorthy P. Ponnusamy, Imayavaramban Lakshmanan, Satyanarayana Rachagani, Eric Cruz, Sushil Kumar, Srustidhar Das, Subodh M. Lele, Judy M. Anderson, Uwe A. Wittel, Michael A. Hollingsworth, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

MUC16 (CA125) belongs to a family of high-molecular weight O-glycosylated proteins known as mucins. While MUC16 is well known as a biomarker in ovarian cancer, its expression pattern in pancreatic cancer (PC), the fourth leading cause of cancer related deaths in the United States, remains unknown. The aim of our study was to analyze the expression of MUC16 during the initiation, progression and metastasis of PC for possible implication in PC diagnosis, prognosis and therapy. In this study, a microarray containing tissues from healthy and PC patients was used to investigate the differential protein expression of MUC16 in PC. MUC16 …

Activated Krasg¹²D Is Associated With Invasion And Metastasis Of Pancreatic Cancer Cells Through Inhibition Of E-Cadherin., Satyanarayana Rachagani, S Senapati, S Chakraborty, Moorthy P. Ponnusamy, Sushil Kumar, Lynette Smith, Maneesh Jain, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

BACKGROUND: Pancreatic cancer (PC) harbours an activated point mutation (Kras(G12D)) in the Kras proto-oncogene that has been demonstrated to promote the development of PC.

METHODS: This study was designed to investigate the effect of the oncogenic Kras(G12D) allele on aggressiveness and metastatic potential of PC cells. We silenced the oncogenic Kras(G12D) allele expression in CD18/HPAF and ASPC1 cell lines by stable expression of shRNA specific to the Kras(G12D)allele.

RESULTS: The Kras(G12D) knockdown cells exhibited a significant decrease in motility (P

CONCLUSIONS: The results of this study suggest that the Kras(G12D) allele promotes metastasis in PC cells partly through the downregulation …

P66shc--A Longevity Redox Protein In Human Prostate Cancer Progression And Metastasis : P66shc In Cancer Progression And Metastasis., Mythilypriya Rajendran, Paul Thomes, Li Zhang, Suresh Veeramani, Ming-Fong Lin

Journal Articles: Biochemistry & Molecular Biology

p66Shc, a 66 kDa proto-oncogene Src homologous-collagen homologue (Shc) adaptor protein, is classically known in mediating receptor tyrosine kinase signaling and recently identified as a sensor to oxidative stress-induced apoptosis and as a longevity protein in mammals. The expression of p66Shc is decreased in mice and increased in human fibroblasts upon aging and in aging-related diseases, including prostate cancer. p66Shc protein level correlates with the proliferation of several carcinoma cells and can be regulated by steroid hormones. Recent advances point that p66Shc protein plays a role in mediating cross-talk between steroid hormones and redox signals by serving as a common …

Elevated Expression Of L-Selectin Ligand In Lymph Node-Derived Human Prostate Cancer Cells Correlates With Increased Tumorigenicity., Prakash Radhakrishnan, Ming-Fong Lin, Pi-Wan Cheng

Journal Articles: Biochemistry & Molecular Biology

Human prostate cancer LNCaP cells including C-33 and C-81 cells were originally derived from the lymph nodes of a patient with metastatic prostate cancer. These two cells were employed for characterization of L-selectin ligand and in vitro tumorigenicity, because they mimic the clinical conditions of early and late-stage human prostate cancer. C-81 cells exhibit higher in vitro migratory and invasive properties as compared with C-33 cells. We find that the L-selectin ligand and mucin glycan-associated MECA-79 epitope were elevated in C-81 cells. An increase of these glycotopes positively correlates with elevated tumorigenicity and expression of key glycosyl- and sulfotransferase genes. …

Muc4 Activates Her2 Signalling And Enhances The Motility Of Human Ovarian Cancer Cells., Moorthy P. Ponnusamy, A. P. Singh, Maneesh Jain, S. Chakraborty, N. Moniaux, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

The mucin MUC4 is a high molecular weight transmembrane glycoprotein. It consists of a mucin-type subunit (MUC4alpha) and a transmembrane growth factor-like subunit (MUC4beta). The mucin MUC4 is overexpressed in many epithelial malignancies including ovarian cancer, suggesting a possible role in the pathogenesis of these cancers. In this study, we investigated the functional role of MUC4 in the human ovarian cancer cell line SKOV3. The mucin MUC4 was ectopically expressed by stable transfection, and its expression was examined by western blot and confocal microscopy analyses. The in vitro studies demonstrated an enhanced motility of MUC4-expressing SKOV3 cells compared with the …