Hormones, Receptors, and Hormones, Receptors, and Signal TransductionSignal Transduction

MCB 720MCB 720

March 2, 2010March 2, 2010

John J. Kopchick, Ph.D.John J. Kopchick, Ph.D.

Hormone -Receptor Hormone -Receptor InteractionsInteractions

HormoneHormone stems from a stems from a Greek Greek term term meaningmeaning ““to spur onto spur on.”.”

General General principlesprinciples

Higher organisms, from the fruit fly to Higher organisms, from the fruit fly to humans, are comprised of humans, are comprised of

cells.cells. The The cells cells often unite to form often unite to form tissuetissue

which come together to form which come together to form organsorgans which together make up which together make up the the organismorganism..

Cells of an Cells of an organismorganism do not live in do not live inisolation.isolation.

TheThe communicationcommunication between cells between cells ultimately controls growth, ultimately controls growth,

differentiation, and metabolic differentiation, and metabolic processes within the organism.processes within the organism.

CommunicationCommunication between cells is between cells is often by often by direct cell to cell contact.direct cell to cell contact.

CommunicationCommunication frequently occurs frequently occurs between cells over between cells over shortshort and and

long long distances.distances.

General principles contGeneral principles cont......

In cases of short and long distance In cases of short and long distance communication, a substance may be communication, a substance may be releasedreleased by one cell and recognized by a by one cell and recognized by a different different targettarget cell.cell.

In the target cell, a In the target cell, a specificspecific response is response is induced.induced.

Cells use an amazing number of Cells use an amazing number of signalingsignaling chemicals. chemicals.

These signaling molecules are termed These signaling molecules are termed ““hormoneshormones.”.”

The ability of a The ability of a hormonehormone to to induce induce a a response in response in a a targettarget cell is usually cell is usually mediated by a mediated by a hormone hormone receptorreceptor on, or on, or in, the target cell.in, the target cell.

General characteristicsGeneral characteristicsof hormonesof hormones

Hormones are molecules synthesized by Hormones are molecules synthesized by specific specific tissue. Classically these tissue tissue. Classically these tissue were called were called glandsglands..

Hormones are secreted directly into the Hormones are secreted directly into the blood blood which which carriescarries them to their sites them to their sites of action.of action.

Hormones are present at very Hormones are present at very lowlow levels in levels in the the circulatory system.circulatory system.

Hormones specifically affect or alter the Hormones specifically affect or alter the activities of the responsive tissue activities of the responsive tissue

((targettarget tissue).tissue). Hormones act specifically via Hormones act specifically via receptorsreceptors

located located on, or in, on, or in, targettarget tissue. tissue.

Hormone/Receptor InteractionHormone/Receptor InteractionSecondary SignalsSecondary Signals

Possible pathways of transmission of hormonal signal. Each hormone can work through one or more receptors; each hormone-receptor complex can work through one or more mediator proteins (either G proteins or other signaling mechanism), and each mediating protein or enzyme activated by hormone-receptor complexes can affect one or more effectors functions.

HH11 RR11 GG11 EE11Range of possible pathways

HormoneHormone ReceptorReceptor Mediator Mediator ProteinProtein

EffectorsEffectors

HH22 RR22 GG22 EE22

Hormones

Reproduction

Growth & Development

Maintenance of internal environment

Energy production, utilization & storage

The four primary arenasThe four primary arenas of hormone action of hormone action

DefinitionsDefinitionsEndocrineEndocrine -- Refers to the internal secretion Refers to the internal secretion

of biologically active substances.of biologically active substances.ExocrineExocrine - - Refers to secretion outside the body, for Refers to secretion outside the body, for

example, through sweat glands, mammary example, through sweat glands, mammary glands, or ducts lead to the gastrointestinal.glands, or ducts lead to the gastrointestinal.

HormoneHormone - - Substances released by an endocrine Substances released by an endocrine gland and transported through the gland and transported through the bloodstream to another tissue where it acts bloodstream to another tissue where it acts to regulate functions in the target tissue to regulate functions in the target tissue (classic definition).(classic definition).

ParacrineParacrine - Hormones that act locally on cells that - Hormones that act locally on cells that did not produce them.did not produce them.

AutocrineAutocrine - Hormones that act on cells that - Hormones that act on cells that produced them.produced them.

ReceptorsReceptors --Hormones bind to receptors molecules on Hormones bind to receptors molecules on cells. A receptor must specifically recognize cells. A receptor must specifically recognize the hormone from the numerous other the hormone from the numerous other molecules in the blood and transmit the molecules in the blood and transmit the hormone binding information into a cellular hormone binding information into a cellular specific action.specific action.

EndocrinEndocrinee

Blood vesselBlood vessel

Distant target Distant target cellscells

Hormone Hormone secretion into secretion into blood by blood by endocrine glandendocrine gland

ParacriParacrinene

Secretory Secretory cellcell

Adjacent target cellAdjacent target cell

AutocrinAutocrinee

Target sites on same cellTarget sites on same cell

ReceptorReceptor

Hormone or other Hormone or other extra cellular signalextra cellular signal

H HHH

H

HR HR

HR HR

H

H

HH

H H R

NN

H

HR R

RH

N

N

N

N

H H

Endocrine cell Neurotransmitter cell

Autocrine

Paracrine

AutocrineBloodvessel

Axon

Neurotransmitter &hormone target cell(H,hormone; R, receptor; N,neurotransmitter.)(H,hormone; R, receptor; N,neurotransmitter.)

Actions of hormones & Actions of hormones & neurotransmitters & their neurotransmitters & their

interrelationshipsinterrelationships

Examples of Hormones Examples of Hormones and glands that and glands that produce themproduce them

Selected hormones & their functionsSelected hormones & their functions

Insulin Pancreas Controls blood-sugar level and storage of glycogen.

Glucagon Pancreas Stimulates conversion of glycogen to

glucose; raises blood sugar level. Oxytocin Pituitary gland Stimulates contraction of the uterine

muscles and secretion of milk by the mammary glands.

Vasopressin Pituitary gland Controls water excretion by the kidneys; stimulates

contraction of the blood vessels.

Growth hormone Pituitary gland Stimulates growth.

Adrenocorticotrophic Pituitary gland Stimulates the adrenal cortex, which,in turn,releases

hormone (ACTH) several steroid hormones.

Prolactin Pituitary gland Stimulates milk production by the mammary glands

after birth of baby.

Epinephrine Adrenal glands Stimulates rise in blood pressure, acceleration of

heartbeat, decreased secretion of insulin, and increased blood sugar.

HormoneHormone SourcSourcee

PrincipalPrincipal functionsfunctions

Cortisone Adrenal glands Helps control carbohydrate metabolism, salt and water balance, formation and storage of glycogen.Thyroxine & Thyroid gland Increases the metabolic rate of carbohydrates Triiodothyronine and proteins.

Calcitonin Thyroid gland Prevents the rise of calcium and phosphate in the body.Parathyroid Parathyroid gland Regulates the metabolism of calcium and

phosphate in hormone in the body.

Gastrin Stomach Stimulates secretion of gastric juice.

Secretin Duodenum Stimulates secretion of pancreatic juice.Estrogen Ovaries Stimulates development and maintenance of female sexual characteristics.Progesterone Ovaries Stimulates female sexual characteristics and

maintains pregnancy.Testosterone Testes Stimulates development and maintenance of male sexual characteristics.

HormoneHormone SourcSourcee

Principal Principal functionsfunctions

Selected hormones & their functions cont...Selected hormones & their functions cont...

““Generic”Generic”Hormone/Receptor Hormone/Receptor

Interactions Interactions

H R F PP2ndMessenger

Effector

Response

Protein mRNA

Pre-mRNA

Modification

H

Regulation of transcription by hormones that act on the cell surface.

Types of HormonesTypes of Hormones

Catecholamines and Thyroid Catecholamines and Thyroid HormonesHormones

Small and derived from amino acids (epinephrine, Small and derived from amino acids (epinephrine, thryoxine.)thryoxine.)

Steroid Hormones and Vitamin DSteroid Hormones and Vitamin DRelatively small and derived from cholesterolRelatively small and derived from cholesterol

Prostaglandin'sProstaglandin'sRelatively small and derived from fatty acidsRelatively small and derived from fatty acids

Proteins or PolypeptidesProteins or Polypeptidesrelatively large and derived from translation of relatively large and derived from translation of

hormone hormone specific mRNA (growth hormone, insulin)specific mRNA (growth hormone, insulin)

Thyroid HormonesThyroid Hormones Synthesized solely in the Synthesized solely in the thyroidthyroid gland ( gland ( T4T4; ;

3’,5’,3,5-L-tetra-iodothyronine).3’,5’,3,5-L-tetra-iodothyronine). Majority of the active form, Majority of the active form, T3T3 (3’,3,5-L-tri- (3’,3,5-L-tri-

iodothyronine), is produced in the peripheral tissues iodothyronine), is produced in the peripheral tissues through deiodination of through deiodination of T4T4..

Thyroid gland cells concentrates Thyroid gland cells concentrates iodineiodine for thyroid for thyroid hormone synthesis.hormone synthesis.

IodineIodine is attached to is attached to tyrosinetyrosine residues on a residues on a protein, termed thyroglobulin. Tyrosine residues protein, termed thyroglobulin. Tyrosine residues are then coupled together to yield are then coupled together to yield thyroninesthyronines..

Proteolytic digestion of thyroglobulin then yields Proteolytic digestion of thyroglobulin then yields T4T4 and and T3T3 in a in a 10:110:1 ratio. ratio.

Helps in the metabolism of Helps in the metabolism of sugarssugars.. The half life of T4 is The half life of T4 is 7 days7 days and that of T3 is and that of T3 is 1 day.1 day.

HOHO

II

II

II

II II

II

II

OO

OO CHCH22 CCHH

NHNH33++

COO COO --

CHCH22 CCHH

NHNH33++

COO COO --

Tyroxine [Tetra-iodothyronine (T4)]Tyroxine [Tetra-iodothyronine (T4)]

Tri-iodothyronine (T3)Tri-iodothyronine (T3) Increase of Increase of oxidation of sugars oxidation of sugars by most body by most body cells; induction of cells; induction of some enzymessome enzymes

Thyroid Thyroid HormonHormoneses

HOHO

Response

Protein mRNA

Pre-mRNA

PPR

F F FR

PB

Regulation of Regulation of transcription transcription by thyroid hormones. by thyroid hormones. TT33 and and TT44 are tri-iodotyronine and tyroxine, are tri-iodotyronine and tyroxine, respectively.respectively.

TT33

TT44

TT33

TT44

TT33

TT33

TT33

Steroid HormonesSteroid Hormones Produced in the Produced in the adrenals, ovaries, testes, and adrenals, ovaries, testes, and

placentaplacenta.. Derived from Derived from cholesterolcholesterol.. EnzymesEnzymes in the various glands control the final in the various glands control the final

product. For example, cytochrome P450c11 which product. For example, cytochrome P450c11 which is located in the adrencortical cells, is involved in is located in the adrencortical cells, is involved in coritsolcoritsol production. This enzyme is lacking in the production. This enzyme is lacking in the gonads, that do not produce cortisol or gonads, that do not produce cortisol or aldosterone.aldosterone.

Gonads, however, can produce Gonads, however, can produce dihydroxytestosterone, estradiol, or dihydroxytestosterone, estradiol, or progesteroneprogesterone depending upon the enzymes depending upon the enzymes present in the gonadal tissue.present in the gonadal tissue.

Over Over 50 50 different steroid metabolites have been different steroid metabolites have been described.described.

Cholesterol Metabolism

Steroid Hormones

S SS S

SSS

S

S

S S

SPB

HSPHSP

HSPHSP

R

R R R RHSPHSP

HSPHSP

R

F R R PP

Response

Protein mRNA

pre-mRNA

F

Regulation of transcription by steroid Regulation of transcription by steroid hormoneshormones

CatecholaminesCatecholamines Are synthesized in Are synthesized in nervous tissuesnervous tissues from which from which

the adrenal medulla is derived.the adrenal medulla is derived. Adrenal medullaAdrenal medulla is the major source for is the major source for

circulating circulating epinephrineepinephrine.. Synthesized from Synthesized from tyrosinetyrosine which is converted to which is converted to

dihydroxyphenylalanine (dihydroxyphenylalanine (DOPADOPA) by tyrosine ) by tyrosine hydroxylases.hydroxylases.

Subsequent conversions to Subsequent conversions to dopaminedopamine and then and then to nor epinephrine which is released by most to nor epinephrine which is released by most catecholamine-producing cells of the body.catecholamine-producing cells of the body.

In the adrenal medulla and a few other tissue, nor In the adrenal medulla and a few other tissue, nor epinephrine is converted to epinephrine is converted to epinephrineepinephrine..

The half life is The half life is 1-2 minutes1-2 minutes..Flight, fright, or fight!Flight, fright, or fight!

Prostaglandins and Prostaglandins and LeukotrienesLeukotrienes

They can be produced by most cells depending upon They can be produced by most cells depending upon lipid and enzyme content of the cells.lipid and enzyme content of the cells.

Arachidonic acidArachidonic acid, which is derived from lipid , which is derived from lipid metabolism, is the precursor compound.metabolism, is the precursor compound.

Depending upon the Depending upon the lipoxygenaselipoxygenase present in the present in the cell, either, HETE, prostaglandin (G2) cell, either, HETE, prostaglandin (G2) or leukotrienesor leukotrienes

CyclooxygenaseCyclooxygenase (involved in PGG(involved in PGG2 2 synthesis) is synthesis) is widely distributed throughout the body and is widely distributed throughout the body and is inhibited by aspirin, indomethacin, and other inhibited by aspirin, indomethacin, and other nonsteroidal and anti-inflammatory agents. nonsteroidal and anti-inflammatory agents.

The half-life is a few The half-life is a few secondsseconds..

Several COX inhibitors!! - ProblemsSeveral COX inhibitors!! - Problems

Hormone AntagonistsHormone Antagonists

Examples of hormone antagonists used in Examples of hormone antagonists used in therapytherapyAntagonist toAntagonist to UseUse

Growth Hormone Acromegaly, DiabetesGrowth Hormone Acromegaly, Diabetes

ProgesteroneProgesterone Contraceptive, abortionContraceptive, abortion

GlucocorticoidGlucocorticoid Spontaneous Cushing’s Spontaneous Cushing’s SyndromeSyndrome

Mineralo-corticoid Primary and secondary Mineralo-corticoid Primary and secondary

mineralocorticoid excessmineralocorticoid excess

AndrogenAndrogen Prostate cancer Prostate cancer

EstrogenEstrogen Breast cancerBreast cancer

GnRHGnRH Prostate cancer Prostate cancer

-Adrenrgic-Adrenrgic Hypertension, Hypertension, hyperthyroidismhyperthyroidism

ProstaglandinProstaglandin Acute and chronic Acute and chronic inflammatory inflammatory disease disease

TamoxifinTamoxifin

Hormone Hormone ReceptorsReceptors

andand

Signal Signal TransductionTransduction

Hormone Hormone ReceptorsReceptors

Cell surface Cell surface membranemembrane receptorsreceptors

Polypeptide hormones and catecholamines

CytoplasmicCytoplasmic receptorsreceptorsMost steroid and thyroid hormones

NuclearNuclear receptors receptorsestrogens

Secondary Messengeror Secondary Signal

CellularTrafficking

Enzymes

Activated Inhibited

Nucleus DNA SynthesisRNA Synthesis

ProteinSynthesis

MembraneEffects

Receptor

Effector

PlasmaMembrane

Hormone

A general model for the action of peptide hormones, catecholamines, A general model for the action of peptide hormones, catecholamines, and other membrane-active hormones. The hormone in the extra and other membrane-active hormones. The hormone in the extra cellular fluid cellular fluid bindsbinds to the receptor and to the receptor and activatesactivates associated associated effector(s)effector(s) systems, that may or may not be in the same molecule. systems, that may or may not be in the same molecule. This activation results in generation of an intracellular signal or This activation results in generation of an intracellular signal or second messengersecond messenger that, through a variety of common and branched that, through a variety of common and branched pathways, produces the final pathways, produces the final effectseffects of the hormone on metabolic of the hormone on metabolic enzyme activity, protein synthesis, or cellular growth and enzyme activity, protein synthesis, or cellular growth and differentiation.differentiation.

Receptors that span Receptors that span the membrane Seven the membrane Seven

timestimes

cAMPcAMPcAMP: synthesis and degradationcAMP: synthesis and degradation

cAMP

Amino acid Amino acid PhosphorylationPhosphorylation is is very important in intracellular very important in intracellular

signal transductionsignal transduction

S Serine

Protein Kinases – transfer terminal Phosphate groups from ATP to Serine, Threonine, or Tyrosine residues in proteins

Result in activation or inactivation of the recipient protein !

ATPATPATP

S Serine

Threonine

Y Tyrosine

Amino acidsthat can be

phosphorylated

Peptide hormone Peptide hormone receptorsreceptors

Huising, et.al.J. Endo. 2006. 189:1-25

General View of

Metabolism

Levels of blood sugar Levels of blood sugar (glucose)(glucose) regulate secretion regulate secretion

of hormones from of hormones from the pancreasthe pancreas

Pancreas secretes Pancreas secretes insulininsulin when glucose when glucose

levels are highlevels are high

InsulinInsulin binds to binds to insulin receptors insulin receptors on fat and muscle on fat and muscle and “promotes” and “promotes” glucose uptakeglucose uptake

Overall effect: blood Overall effect: blood glucoseglucose

levels return to normallevels return to normal

Glucose Tolerance Test

The Insulin ReceptorThe Insulin Receptor

Responsible for clearance of Responsible for clearance of glucoseglucose

In addition to binding insulin, it In addition to binding insulin, it possesses a tyrosine kinase possesses a tyrosine kinase activityactivity

It is involved in many cellular It is involved in many cellular activitiesactivities

Glucose Transporter Intracellular Trafficking

Insulin Receptor

Tyrosinekinase

Insulin-mediated glucose transport signaling pathway

Insulin

P IRS

PI3K

Akt P

IR

Glut4

Insulin-mediated glucose transport signaling pathway

Cell membrane

Xiao Chen, 2006Xiao Chen, 2006

Insulin

P IRS

PI3K

Akt P

IR

glucose

Insulin-mediated glucose transport signaling pathway

Cell membrane

Insulin-mediated glucose transport signaling pathway

Xiao Chen, 2006Xiao Chen, 2006

Time, Nov, 2006USA Life Expectancy; Low = 73.6; High = 80.0

Obesity is a Global Pandemic DiseaseObesity is a Global Pandemic Disease

USA TodayFeb. 9, 2010

USA TodayFeb. 9, 2010

     Reduce

USA TodayFeb. 9, 2010

41 grams

Time, Nov, 2006USA Life Expectancy; Low = 73.6; High = 80.0

Insulin Signaling Pathways by C. Hooper http://www.abcam.com/index.html?Insulin Signaling Pathways by C. Hooper http://www.abcam.com/index.html?pageconfig=resource&rid=10602&pid=7pageconfig=resource&rid=10602&pid=7

Cartoon of Intracellular Signaling System Cartoon of Intracellular Signaling System Used By Many Peptide Hormones and Used By Many Peptide Hormones and

Growth FactorsGrowth Factors

For exampleFor example– InsulinInsulin– EGFEGF

Tyrosine kinase receptors are a family of receptors with a similar structure. They each have a tyrosine kinase domain (which phosphorylates proteins on tyrosine residues), a hormone binding domain, and a carboxyl terminal segment with multiple tyrosines for autophosphorylation. When hormone binds to the extra cellular domain the receptors aggregate.

When the receptors aggregate, the tyrosine kinase domains phosphorylate the C terminal tyrosine residues.

This phosphorylation produces binding sites for proteins with SH2 domains. GRB2 is one of these proteins. GRB2, with SOS bound to it, then binds to the receptor complex. This causes the activation of SOS.

SOS is a guanyl nucleotide-release protein (GNRP). When this is activated, it causes certain G proteins to release GDP and exchange it for GTP. Ras is one of these proteins. When ras has GTP bound to it, it becomes active.

Activated ras then causes the activation of a cellular kinase called raf-1.

Raf-1 kinase then phosphorylates another cellular kinase called MEK. This cause the activation of MEK.

Activated MEK then phosphorylates another protein kinase called MAPK causing its activation. This series of phosphylating activations is called a kinase cascade. It results in amplification of the signal.

Among the final targets of the kinase cascade are transcriptions factors (fos and jun showed here). Phosphorylation of these proteins causes them to become active and bind to the DNA, causing changes in gene transcription.

Adapted from: Dr. Donald F. Slish, Biological Sciences Department,

Plattsburgh State University, Plattsburgh, NY.

Examples of therapeutics Examples of therapeutics developed based on these developed based on these types of receptors and the types of receptors and the associated tyrosine kinase associated tyrosine kinase

signaling systemsignaling system

Erbitux – ImcloneErbitux – Imclone Iressa - AstraZeneca Iressa - AstraZeneca

Gleevec – Novartis Gleevec – Novartis Herceptin - GenentechHerceptin - Genentech

EGF Receptor Signal Transduction Pathway

SIGMA-ALDRICH

Tyrosine kinaseTyrosine kinase

Cell ProliferationCell Proliferation

Epidermal Growth Factor ReceptorEpidermal Growth Factor Receptor

EGF

ReceptorReceptor

DimerizationDimerization

Cell Cell MembraneMembrane

Cysteine Cysteine RichRich

DomainDomain

Tyrosine KinaseDomain

EGF

Signal Transduction

P P

******

******

EGFR FamilyEGFR Family

The epidermal growth factor (EGF) family of receptor tyrosine kinases consists of four receptors,

ErbB1 (EGFR) ErbB2 (Her/Neu) ErbB3 (HER3) ErbB4 (HER4).

Non-small cell lung cancerNon-small cell lung cancer

Non-small cell lung cancer comprises over 75% of all lung cancers. In 2006, more than 338,000 cases of the disease are expected to be diagnosed in the seven major pharmaceutical markets. High unmet needs of therapy still persist for this tumor type. The overall survival of NSCLC patients remains below 12 months.

The EGfR is expressed on these cells.

Epidermal Growth Factor Receptor in Non–Small-Cell Lung Carcinomas: Correlation Between Gene Copy Number and Protein

Expression and Impact on Prognosis Fred R. Hirsch, Marileila Varella-Garcia, Paul A. Bunn, Jr, Michael V. Di Maria, Robert Veve,

Roy M. Bremnes, Anna E. Barón, Chan Zeng, Wilbur A. Franklin

Journal of Clinical Oncology, Vol 21, 2003: 3798-3807, 2003

• The percentage of EGFR positive tumor cells per slide (0% to 100%) was multiplied by the dominant intensity pattern of staining (1, negative or trace; 2, weak; 3, moderate; 4, intense); therefore, the overall score ranged from 0 to 400 (Fig 1). Specimens with scores 0 to 200, 201 to 300, and 301 to 400 were respectively classified as having negative or low, intermediate, and high levels of expression.

 Influence of histological type, smoking history and chemotherapy on survival after first-line therapy in patients with advanced non-

small cell lung cancer

Itaya , Yamaoto, Ando, Ebisawa, Nakamura, Murakami, Asai, Endo and Takahashi Cancer Science

Volume 98, Page 226, 2007

• For overall survival, smoking history and histology were significant prognostic factors. The 2-year overall survival rates were as follows: smokers, 17%; non-smokers, 52%, P < 0.0001;

Iressa (gefitinib tablets)AstraZeneca.

IRESSA is indicated as monotherapy for the continued treatment

of patients with locally advanced or

metastatic non-small cell lung cancer after

failure of both platinum-based and

docetaxel chemotherapies who

are benefiting or have benefited from

IRESSA.

Iressa (gefitinib tablets)AstraZeneca.

• Mechanism of Action

• The mechanism of the clinical antitumor action of gefitinib is not fully characterized.

• Gefitinib inhibits the intracellular phosphorylation of numerous tyrosine kinases associated with transmembrane cell surface receptors, including the tyrosine kinases associated with the epidermal growth factor receptor (EGFR-TK).

• EGFR is expressed on the cell surface of many normal cells and cancer cells. No clinical studies have been performed that demonstrate a correlation between EGFR receptor expression and response to gefitinib.

Gefitinib is an anilinoquinazoline with the

chemical name 4-Quinazolinamine, N-(3-

chloro-4- fluorophenyl) -7-methoxy-6- [3-4-

morpholin) propoxy]

C22H24ClFN4O3

Zactima Tyrosine Kinase Inhibitor for Treatment

of Lung Cancer

• Zactima (ZD6474) is an orally available Tyrosine Kinase Inhibitor (TKI) under development by AstraZeneca for the treatment of solid tumours. Following promising results in early clinical trials, Zactima has now progressed to phase III development in Non-Small Cell Lung Cancer (NSCLC), its primary indication.

• If phase III trials prove successful, analysts believe Zactima could be on the market by 2008 and help to fill the void left by recent setbacks with Iressa (gefitinib), its first TKI for lung cancer.

• At the beginning of the year, AstraZeneca withdrew its marketing application for Iressa in Europe. This followed the release of new long-term data that showed it to be no better than placebo in prolonging patients' lives.

• Meanwhile, in the US Iressa will soon be available only to existing NSCLC patients who have already shown treatment benefit and will not be prescribed to new patients. While Iressa has stalled in Europe and the US, it is approved in more than 30 countries elsewhere.

http://www.drugdevelopment-technology.com/projects/zactima/AstraZeneca

BCR - ABL

• The exact chromosomal defect in Philadelphia chromosome is translocation. Parts of two chromosomes, 9 and 22, swap places. The result is that part of the BCR ("breakpoint cluster region") gene from chromosome 22 (region q11) is fused with part of the ABL gene on chromosome 9 (region q34). Abl stands for "Abelson", the name of a leukemia virus which carries a similar protein.

• The result of the translocation is a protein of p210 or sometimes p185 weight (p is a weight fraction of cellular proteins in kDa). The fused "bcr-abl" gene is located on the resulting, shorter chromosome 22. Because abl carries a domain that can add phosphate groups to tyrosine residues (tyrosine kinase) the bcr-abl fusion gene is also a tyrosine kinase. (Although the bcr region is also a serine/threonine kinase, the tyrosine kinase function is very relevant for therapy, as will be shown.)

• The fused bcr-abl protein interacts with the interleukin 3beta(c) receptor subunit. The bcr-abl transcript is constitutively active, i.e. it does not require activation by other cellular messaging proteins. In turn, bcr-abl activates a number of cell cycle-controlling proteins and enzymes, speeding up cell division. Moreover, it inhibits DNA repair, causing genomic instability and potentially causing the feared blast crisis in CML.

BCR-ABL• The exact chromosomal defect in Philadelphia chromosome is translocation. Parts of two

chromosomes, 9 and 22, swap places. The result is that part of the BCR ("breakpoint cluster region") gene from chromosome 22 (region q11) is fused with part of the ABL gene on chromosome 9 (region q34). Abl stands for "Abelson", the name of a leukemia virus which carries a similar protein.

• The result of the translocation is a protein of p210 or sometimes p185 weight (p is a weight fraction of cellular proteins in kDa). The fused "bcr-abl" gene is located on the resulting, shorter chromosome 22. Because abl carries a domain that can add phosphate groups to tyrosine residues (tyrosine kinase) the bcr-abl fusion gene is also a tyrosine kinase. (Although the bcr region is also a serine/threonine kinase, the tyrosine kinase function is very relevant for therapy, as will be shown.)

• The fused bcr-abl protein interacts with the interleukin 3beta(c) receptor subunit. The bcr-abl transcript is constitutively active, i.e. it does not require activation by other cellular messaging proteins. In turn, bcr-abl activates a number of cell cycle-controlling proteins and enzymes, speeding up cell division. Moreover, it inhibits DNA repair, causing genomic instability and potentially causing the feared blast crisis in CML. (Chronic myelogenous leukemia)

Gleevec (imatinib mesylate, aka STI-571)

FDA APPROVES GLEEVEC FOR LEUKEMIA TREATMENT

The Food and Drug Administration today announced the approval of Gleevec (imatinib mesylate, also known as STI-

571), a promising new oral treatment for patients with chronic myeloid leukemia (CML) -- a rare life-threatening

form of cancer. FDA reviewed the marketing application for Gleevec in less than three months under its "accelerated

approval" regulations.

Novartis, May 10, 2001

Used in the treatment of Chronic Myeloid Leukemia (CML) and Gastrointestinal Stromal Tumors (GIST)

Mechanism of Action

Imatinib mesylate is a protein-tyrosine kinase inhibitor that inhibits the Bcr-Abl tyrosine kinase, the constitutive abnormal tyrosine kinase created by the Philadelphia chromosome abnormality in chronic myeloid leukemia (CML). It inhibits proliferation and induces apoptosis in Bcr-Abl positive cell lines as well as fresh leukemic cells from Philadelphia chromosome positive chronic myeloid leukemia. In colony formation assays using ex vivo peripheral blood and bone marrow samples, imatinib shows inhibition of Bcr-Abl positive colonies from CML patients. In vivo, it inhibits tumor growth of Bcr-Abl transfected murine myeloid cells as well as Bcr-Abl positive leukemia lines derived from CML patients in blast crisis.

In vitro studies demonstrate imatinib is not entirely selective; it also inhibits the receptor tyrosine kinases for platelet-derived growth factor (PDGF) and stem cell factor (SCF), c-Kit, and inhibits PDGF mediated cellular events

Gleevec (Novarits)

Monoclonal Antibody TherapyMonoclonal Antibody Therapy

Antibody to EGF R binds and blocks EGF from Antibody to EGF R binds and blocks EGF from bindingbinding

Cell Cell MembraneMembrane

Tyrosine KinaseDomain

EGF

Erbitux, ImcloneErbitux, Imclone

Therefore, no tyrosine kinase Therefore, no tyrosine kinase activity andactivity and

no intracellular signalingno intracellular signaling

Herceptin

is the first humanized antibody approved for the treatment of HER2-positive metastatic breast

cancer. Herceptin is designed to target and block the function of HER2 protein over expression.

Genentech

HER 2 = Human Epidermal Growth HER 2 = Human Epidermal Growth Factor Receptor 2Factor Receptor 2

Herceptin, Herceptin, a monoclonal antibody, a monoclonal antibody,

binds to HER2binds to HER2and ultimately results and ultimately results

in destruction of the cell in destruction of the cell

So two targets to inhibit EGF/EGFR So two targets to inhibit EGF/EGFR signalingsignalingEGF

ReceptorReceptor

DimerizationDimerization

Cell Cell MembraneMembrane

Tyrosine KinaseDomain

EGF

Signal Transduction

P P

11

22

Colored slide: D-88Colored slide: D-88

Diabetes   Diabetes - from the Greek word, diabetes, meaning “a crossing over or passing through”. Any of several metabolic disorders marked by excessive discharge of urine and persistent thirst. (The American Heritage Dictionary).  Diabetes mellitus - a chronic disease of pancreatic origin, characterized by insulin deficiency, subsequent inability to utilize carbohydrates, excess sugar in the blood and urine, excessive thirst, hunger, and urination, weakness, emaciation, imperfect combustion of fats resulting in acidosis, and, without injection of insulin, results in coma and death. (The American Heritage Dictionary).

Diabetes, con’t.Diabetes, con’t.

Type IType I or or Insulin Dependent Insulin Dependent Diabetes MellitusDiabetes Mellitus (IDDM)(IDDM) – Also called – Also called juvenilejuvenile diabetes - diabetes - lack of insulinlack of insulin

Type IIType II or or Non Insulin Dependent Non Insulin Dependent Diabetes MellitusDiabetes Mellitus (NIDDM)(NIDDM) – Also – Also called called adultadult onset diabetes - onset diabetes - insulin insulin present but cells do not respond present but cells do not respond that is they are“insulin resistant”.that is they are“insulin resistant”.

 16-20 million Americans have diabetes.

 385,000 diabetes die each year.

 625,000 new cases each year.

 Every minute of every day, someone new is

diagnosed with diabetes. 

127,000 children (younger that age 20) have diabetes. 

11% of the U.S. population, age 65-74, has diabetes. 

 

Facts: (Diabetes 1996 Vital Statistics, ADA)

Diabetic eye disease (retinopathy): by 15 years after diagnosis of diabetes, retinopathy is present in

97% of insulin users and 80% of non-insulin users.

About 20% of people with diabetes have kidney disease (nephropathy).

 40% of the deaths associated with diabetes are due to heart disease.

Diabetes, con’t.Diabetes, con’t.

  

  Type I or insulin-dependent diabetes mellitus (IDDM) - Low or absent levels of endogenous insulin. Dependent on insulin therapy to prevent ketoacidosis and sustain life. Onset predominantly before age 30 but can occur at any age. Onset is usually abrupt and patients are usually thin. Cause appears to be a combination of genetic and environmental determinants. Pancreatic islet cells are destroyed.  

Types of diabetes mellitus(Diabetes 1996 Vital Statistics, ADA)

Type II or non-insulin dependent diabetes mellitus (NIDDM) - Normal to High insulin levels characterize most patients, indicating insulin resistance in tissues. Often see development of low insulin levels as the disease progresses. Patients are not prone to ketoacidosis during normal circumstances. Although not dependent on insulin therapy for survival, many require it for adequate blood glucose control. Onset is predominantly after age 40, particularly in whites, and often asymptomatic; most patients are obese. Cause appears to be a combination of genetic and environmental lifestyle determinants. Drugs are available to promote insulin release from the pancreas or to allow cells to be more sensitive to insulin action.

Gestational Diabetes Mellitus (GDM) - Glucose intolerance that has its onset or recognition during pregnancy. Associated with older age, obesity, and family history of diabetes. Risk for subsequent NIDDM is increased. Newborn offspring often have macrosomia and may also be at increased risk for developing NIDDM.

 

Diabetes insipidus - Caused by the total or partial lack of the hormone vasopressin, also called antidiuretic hormone. Blood glucose is normal, but increased urine output with accompanying thirst.

 

Other types of diabetes - Diabetes secondary to other conditions with hyperglycemia at a level diagnostic of diabetes.

 

Impaired Glucose Tolerance (IGT) - Blood glucose levels that are higher than normal but not diagnostic for diabetes mellitus. Risk for subsequent NIDDM is increased.

 

Types of diabetes, con’t.Types of diabetes, con’t.