Specific aims: EGFR and c-Met are receptor tyrosine kinases (RTKs), and tyrosine kinase inhibitors (TKIs) against these receptors have been initially effective when prescribed to patients in combination with traditional chemotherapy or radiation. However, the overall efficacy of TKIs is limited due to the development of resistance as seen through clinical trials in NSCLC. Epithelial Mesenchymal Transition (EMT) is a process by which epithelial cells undergo phenotypic and morphological changes to acquire mesenchymal characteristics including increased motility and invasiveness. Currently, the role of EMT in TKI drug resistance is poorly understood. EMT results in loss of tight junction proteins such as E-cadherin and upregulation of transcriptional repressors of these proteins such as ZEB1. Recently, protein arginine methyl transferase 1 (PRMT1) has been shown to be an important regulator of EMT, cancer cell migration and metastasis. However, the role of PRMT1 in TKI resistance is not known. In this study, we propose to evaluate the role of EMT proteins in TKI resistance using H2170 and H358 cell lines (wild type EGFR) that were made resistant to an EGFR inhibitor, erlotinib and a c-Met inhibitor, SU11274 and a combination of both. H3255 cell line (with L858R EGFR mutation), and H1975 cell line with L858R and T790M EGFR mutations which we have made resistant to erlotinib will also be used. Our recent in vitro studies indicate that TKI resistance may be due to the activation
While completing a BS degree in Cell and Molecular Biology at the University of Michigan, I was able to focus on a small independent project at Wicha lab, investigating CSC epithelial-mesenchymal and mesenchymal-epithelial transition states in breast tumors, their clinical relevance, and how scientists may push either transition in various cell lines. Throughout this project, I became familiar with planning and running molecular biology experiments, which requires detailed knowledge especially in analysis, trouble-shooting, and developing further
Significance: understanding the mechanism of drug resistance in cancer leads to developing more potent drugs.
Cancer, medically called ‘tumorigenesis’ (Thaker, Lutgendorf, & Sood, 2007, p.430) occurs when cells in the body orient themselves for malignant growth. Such cells show ‘self-sufficiency in growth signals’, are ‘insensitive to anti-growth signals’ and have ‘limitless replicative potential’ (Thaker, Lutgendorf, & Sood, 2007, p.430). Once a particular set of cells become malignant, the malignancy can spread to other set of cells in different organs due to ‘crosstalk’ between the affected cells and their surrounding ‘tissues’ and ‘micro-environments’(Thaker, Lutgendorf, & Sood, 2007, p.430).
Cancer cells displayed marked alterations in pro-growth signaling pathways and key metabolic pathways relative to non-tumorigenic differentiated cells, often due to loss of tumor suppressor genes and oncogenic driver mutations. The remodeled signaling and metabolic profiles of cancer cells support not only their aberrant proliferation, but also their survival. Further factors such as intra-tumoral heterogeneity, altered redox status, and epigenetic modifications all contribute to the ability of certain tumors to develop drug resistance and persist under standard treatments.
Cancer is listed as the second most common cause of death in western countries; particularly, in adults. Though it has a long antiquity, its prevalence and incidence today is pervasive and the war on cancer has not been promising. Malignant neoplasia is characterized by uncontrolled growth and the ability to metastasize or spread from the original site. Cancer results from mutations that promote cell proliferation and inhibit cell adhesion (metastasis). According to the National Cancer Institute (2016), “Cancer can also spread regionally,
Crizotinib (PF-02341066) is a potent inhibitor of c-Met and ALK. Anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer (NSCLC) is a molecular subtype of NSCLC with at least 27 ALK-fusion variants identified. c-Met is the prototypic member of RTKs, which is the only known high-affinity receptor for hepatocyte growth factor (HGF). Binding of HGF to the c-Met results in receptor multimerization and phosphorylation of multiple tyrosine residues at the intracellular region.
The main focus of this article was to Crizotinib as an inhibitor for ALK-rearragements in the Non-Small Cell Lung Cancer (NSCLC). The drug was first developed because of the ability for a diagnostic fluorescent in situ hybridization assay to be used to detect ALK-rearranged NSCLC. Pfizer has developed this drug to inhibit ALK and MET in many cancers that are associated with mutations in these specific genes. It has recently been shown to have an effect against ROS1-rearragements in NSCLC. This article provided better insight on the heterogeneity between ALK and ROS1 rearrangements in different subtypes of NSCLC. There is also information in the research article that sheds light into the future developments for crizotinib for ALK-rearrangements and some diagnostic assays that can detect NSCLC. This drug is important to the future of cancer therapies because it targets a subtype to NSCLC and defines a molecular target for its effectiveness. It can broaden a field which involves personalized therapies
Advance downstream, changes in the tumor silencers TSC1 and TSC2 hyper initiate motioning by mTORC1 (Laplante and Sabatini 2012). This is a critical focus of P13K-Aktsignaling. Additionally, the Ras-ERK pathway is enacted by transformations in Ras, or its downstream target Raf, that reason constitutive initiation of these proteins or by inactivation of GTPase-actuating proteins (Holes, for example, NF1, that empower the hydrolysis of GTP bound to Ras, which prompt its inactivation (Cichowski,2001).
The epidermal growth factor receptor (EGFR) is the cell-surface receptor for extracellular protein ligands. EGFR family has four closely related receptor tyrosine kinases: EGFR (ErbB-1), HER2/c-neu, Her 3 and Her 4. Mutations affecting EGFR expression or activity could lead to cancer.
Both of these events occur because of interactions between the cancer cells and the stromal microenvironment (Weinberg et al., 2014). The degradation of extracellular matrix (ECM) and regulation of cell mesenchymal integrity are require steps (Bonnomet et al., 2010; Woessner, 1991). As known that matric metalloproteins (MMPs) are play an important role on ECM degradation. Type IV collagenase and gelatinase (MMP-2 or MMP-9) are major proteases for ECM degradation leading to migration and intravasation (Martin et al., 2007). Several junction proteins, such as E-cadherin and Vascular-Endothelial cadherin (VE-cadherin), are regular the integrity of cell-cell content and cell-mesenchymal contact (Fleming et al., 2000; Micalizzi et al., 2010). During cancer cells leave the original tumor organ to migrate to the target metastasis organ process, adhesion molecules (e.g., integrin-1 and E-selectin) play a key role in regulating the adhesion of tumor cells to endothelium cells (Yates et al., 2014; Okegawa et al., 2002). On the other hand, when cancer cells leave the original tumor organ to migrate to circulate system by intravasation, then they extravasation into the circulatory system to migrate to the target metastasis organ. The regulation of migration, invasion and adhesion may be an effective strategy for improving the prognosis of
Signaling pathways that result in cell migration are often useful in understanding how cancer cells metastasize. The researchers of Swaminathan et al., 2016 examine how adhesion site assembly occurs while Nader et al., 2016 focuses primarily on the adhesion turnover both are fundamental processes in cell migration. Integrins play a dominant role in nascent integrin-mediated adhesions (NAs) which are important in lamellipodium protrusion and generating traction at focal adhesion points involved in cell motility. Integrins have been extensively studied and are linked to wound healing as well as metastasis in cancer cells (Lawson et al., 2012). When extracellular signals, either chemical or physical, contact the cell surface it triggers a response that induces movement. If the signaling molecule is a growth factor (ex. Epidermal Growth Factor) it could activate a GTPase protein coupled receptor (GPCR). The next is a signal cascade often led by Rabs or Ras (small G-proteins) proteins that are powered by GTPase hydrolysis, which often recruits and activates Wiskott–Aldrich Syndrome protein (WASP) or Scar. Previous studies identified cancer cell that use Rab-coupling to control cell motility by regulating B-intgrins trafficking (Nader et al., 2016). WASP recruits Actin related protein 2 and 3 (Arp2/3) complex to the cell membrane and activates it
The uncontrollable spread of cancer is the principal event which leads to the death in individuals with cancer and it is the greatest barrier of developing cures for cancer. Metastasis is the progressive spread of malignant cancer cells from the primary tumour to secondary organ in distant sites and this potential is dependent on the specific microenvironment which support them to complete each step of the metastatic process (Poste & Fidler 1980). To understand the molecular basis of metastasis, investigators have now separated the complex and highly selective metastasis process into series of steps to try and solve the problems cause by
The diacylglycerol (DAG) mediated regulation of protein kinase C (PKC) family of serine/threonine kinases plays a critical role in several intracellular signaling pathways and the pathology of several diseases including cancer, neurological, cardiovascular, and others. In consequence, PKC isozymes are being actively pursued as the subject of intense research and drug development. Depending on their enzymatic properties and activation mechanism, the mammalian PKC isoenzymes have been categorized into classical (calcium-, DAG-, and phospholipid-dependent), novel (calcium-independent, but DAG- and phospholipid-dependent), and atypical (calcium- and DAG-independent) subgroups. The DAGs selectively interact with the C1 domain of PKC isoenzymes.
A cell is the smallest basic functional unit of a living organism. The cell is composed of organelles that help the cell perform its specialized function. Every cell contains a cell membrane and a cytoplasm, the material that is within the cell but does not include the organelles. The cell membrane is a semi-permeable structure with 2 layers of phospholipids containing embedded proteins. The role of this fluid mosaic model is to monitor the exchange of substances, separate the cytoplasm from the external environment, form a communication between other cells, and act as an identification that protects the cell from unidentifiable substances. Also known as fats, the phospholipids creates a barrier between the layers because they consist of a nonpolar hydrophobic,
Overexpression of vascular endothelial growth factor (VEGF) promotes development of tumor-supportive vasculature, cell survival and migration, and vascular permeability. The expression of VEGF is regulated via several mechanisms including oxygen tension, autocrine and paracrine signaling, and oncogenic signaling.5 VEGF is a homodimeric glycoprotein that binds to VEGF receptors 1 and 2 (VEGFR-1 & VEGFR-2) with high affinity (K¬d ~ 1-10 pM and Kd ~ 10-100 pM, respectively) on the extracellular surface of endothelial cells.5,7 Activation of VGFR, a tyrosine kinase receptor, prompts receptor dimerization and autophosphorylation that initiates signal transduction