Ahmad Roushdy-Prostate Cancer Educational Seminar

8/14/2019 Ahmad Roushdy-Prostate Cancer Educational Seminar

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Prostate CancerProstate Cancer


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Graduation research Project

Partial Fulfillment for the degree of B.Sc. In

Ecology/Biochemistry

Prepared By

Ahmad Salah Roushdy

Supervised By

Professor Ahmad R. Bassiouny

May 2006


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What is the Prostate?What is the Prostate?

A male sex gland

The size of a walnut below the bladder and in

front of the rectum

Produces the fluid that is

part of semen


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Risk Factors for Prostate CancerRisk Factors

for Prostate Cancer

Age Found mainly in

men over age 55. Average

age of diagnosis is 70

Family History Mens

risk is higher if father orbrother is diagnosed

before the age of 60


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Risk Factors continuedRisk Factors continued

Race Prostate cancer is found more often in

African American men then White men. It is less

common in Asian and American Indian men

Dietary factors Evidence suggests that a diet

high in fat may increase the risk of prostate cancerand diets high in fruits and vegetables decrease the

risk


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Symptoms of Prostate Cancer

Symptoms of Prostate Cancer

1. Frequent urination

2. Inability to urinate3. Trouble starting and stopping urination

4. Blood in the urine or semen

5. Painful ejaculation

6. Painful or burning urination


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What Goes WrongWhat Goes Wrong

1. Prostate infections prostatitis

Fairly common in men from the teen years on.

These infections can be brief or long-lasting, mild or severe,

easy or difficult to treat with antibiotics.

Symptoms ofprostatitis can include frequent and/or painful

urination, other urinary difficulties, or pain during sex.


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What Goes Wrong continuedWhat Goes Wrong continued

2. Prostate enlargement benign prostatic hyperplasia.

Unwanted but non-cancerous enlargement of the prostate.

Although men in their twenties can suffer from BPH, it

usually surfaces later in life.

It's estimated that half of all men have BPH by the age of

60, and 90% will suffer from it by age 85


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What Goes Wrong continuedWhat Goes Wrong continued

3. Prostate cancer

Prostate cancer is a malignant tumor that usually

begins in the outer part of the prostate. In most

men, the cancer grows very slowly.Urinary

Bladder

Ejaculatory

Duct

Urethra

Transition

Zone

(BPH)

Central

Zone

Anterior

Fibromuscular

Stroma

Peripheral Zone

(Prostate Cancer)

Rectum


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Detecting Prostate Cancer

Prostate cancer rarely causes symptoms early in the

course of the disease.

Patient may present with advanced and metastatic

prostate cancer.

Today, the majority of prostate cancers are detected

based on Digital Rectal Examination DRE

abnormalities or Prostate Specific Antigen PSA

elevations.


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Normal Function of PSA

Secreted in high concentrations into the seminal fluid

(mg/mL), where it cleaves gel-forming proteins

semenogelin andfibronectin to increase sperm

motility

Normally found in low concentration in sera (ng/mL).

Serum PSA increases as epithelial cell number (tumor

volume) increases.

Pro-PSA (Inactive)

PSA (Active)

Inhibitory Region

Pro-Seminogelin (Inactive) Seminogelin (Active)

Liquefaction of Seminal Fluid


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Forms of PSA in Blood

70-90% of serum PSA is boundto the protease

inhibitor1-Anti-Chymotrypsin (ACT).

10-30% of serum PSA is free and unbound.

Minor amounts (


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Use of PSA as a Marker for

Prostate Cell Growth

PSA elevations may indicate the presence of prostate

disease.

Normal prostatic growth: 0.04ng/mL increase peryear.

BPH: 0.07-0.27ng/mL increase per year.

Prostate Cancer: greater than 0.75ng/mL increase

per year.


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normalnormal

prostateprostate

epitheliumepithelium

histologic

prostate

cancer

localized

prostate

cancer

Progression of Prostate Cancer

tumor suppressor geneinactivation / mutation?

androgen

independent

cancer

metastatic

prostate

cancer

curable incurable


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Genetic Epidemiology ofGenetic Epidemiology of

Prostate CancerProstate Cancer is prostate cancer familial? ..... yesis prostate cancer familial? ..... yes

is the familial clustering compatible withis the familial clustering compatible withMendelian inheritance? ..... yesMendelian inheritance? ..... yes are there susceptibility genes responsible for thisare there susceptibility genes responsible for this

pattern of inheritance? ....?pattern of inheritance? ....?

Use linkage analysis to identify and mapUse linkage analysis to identify and map what can identification of these genes tell us aboutwhat can identification of these genes tell us about

the causes of prostate cancer?the causes of prostate cancer?

Inflammation??Inflammation??


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Novel Prostate CancerNovel Prostate Cancer

GenesGenes

RNASEL (chr1)RNASEL (chr1) (Carpten et al 2002)(Carpten et al 2002)Interferon inducible anti viral defenseInterferon inducible anti viral defense

MSR1MSR1 (chr 8) (Xu et al 2003)(chr 8) (Xu et al 2003)Binds diverse ligands including gram -/+ bacteriaBinds diverse ligands including gram -/+ bacteria

Both of these genes are part of the innate immuneBoth of these genes are part of the innate immuneresponse pathway to fight infectionresponse pathway to fight infection

Mutations inMutations inMSR1MSR1 andandRNASELRNASEL are responsibleare responsiblefor ~10% - 15% of hereditary prostate cancer infor ~10% - 15% of hereditary prostate cancer inJHU family collectionJHU family collection

Mixed results seen in other study populationsMixed results seen in other study populations


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Early Detection ofEarly Detection of

Cancer, Does it makeCancer, Does it make

any difference?any difference? Despite recent progress in treatment, Cancer is theDespite recent progress in treatment, Cancer is the

second leading cause of mortality in developedsecond leading cause of mortality in developed

countries.countries.

Early Detection of Cancer results in better treatmentEarly Detection of Cancer results in better treatment

options and higher survival rates.options and higher survival rates.

Unfortunately, current Cancer diagnostics oftenUnfortunately, current Cancer diagnostics often


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Cancer BiomarkersCancer Biomarkers

They are important tools for Cancer detectingThey are important tools for Cancer detecting

and monitoring.and monitoring.

They serve as hallmarks for the physiologicalThey serve as hallmarks for the physiological

status of a cell at a given time and changestatus of a cell at a given time and change

during the disease progression.during the disease progression.

Used routinely for population screening,Used routinely for population screening,

disease diagnosis, prognosisdisease diagnosis, prognosis..


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Some Established Cancer BiomarkersSome Established Cancer Biomarkers

Hepatoma; testicularcancer

Colon; breast; lung;pancreatic

Prostate

Ovarian

BreastGastrointestinal

Testicular cancer

Alpha-fetoprotein AFP)

Carcinoembryonic antigen(CEA)

Prostate-specific antigen(PSA)

CA125

CA15.3

CA19.9Chroriogonadotropin (hCG)

Cancer typeBiomarker

But none of them has adequate sensitivity, specificity

and predictive value for population screening which leads to

many false-positive results.


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Over many years of developing Cancer Biomarkers, It wasOver many years of developing Cancer Biomarkers, It was

postulated that a molecule may become a reliable Cancerpostulated that a molecule may become a reliable Cancer

Biomarker if it has certain characteristicsBiomarker if it has certain characteristics

1. It should be a secreted or shed protein.

2. Able to diffuse into the circulation during tumor

development and progression.

3. Such proteins should be stable (not degradable).

4. Shouldnt be bound to any inhibitor which could

interfere with their measurements.


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? Why Cancer Proteomics? Why Cancer Proteomics

DNA tells what possibly,DNA tells what possibly,

RNA what probably andRNA what probably and

Proteins what actually happens.Proteins what actually happens.

DNA sequence does not predict if the protein is in an active form.

RNA quantitation does not always reflect corresponding protein levels.

Multiple proteins can be obtained from each gene (alternative

splicing).

Genomics cannot predict post-translational modifications and the

effects thereof.


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Surface-enhancedSurface-enhanced

laser desorption/ionization-laser desorption/ionization-time of flight-mass spectrometry.time of flight-mass spectrometry.

SELDI ProteinChip is a mass spectrometrictechnology that accomplishes protein separation

on a chromatographic chip surface by binding

subsets of proteins from complex mixtures.


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SELDI-TOF-MS consists of 3 majorSELDI-TOF-MS consists of 3 major

componentscomponents


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The array contains either 8 or 16 spots

comprised of a specific

chromatographic treated surface.

Chemically-treated surface

Binds

hydrophobic

molecules

Binds +ve charged

proteins; rich in

Lys, Arg, His

Binds -ve charged

proteins; rich in

Asp, Glu

Proteins that bind

to these metal ions

will be bound to

the chip

General protein

binding surface

which bind via

Ser, Ther, Lys

Chemically-treated surface

Binds

hydrophobic

molecules

Binds +ve

charged proteins;

rich in Lys, Arg,

His

Binds -ve charged

proteins; rich in

Asp, Glu

Proteins that bind

to these metal

ions will be

bound to the chip

General protein

binding surface

which bind via

Ser, Ther, Lys

(Antibody - Antigen) (Receptor - Ligand) (DNA - Protein)

Biologically treated surface

(Antibody - Antigen)(Receptor - Ligand) (DNA - Protein)

Biologically treated surface

Chemically treated surfaces will retain whole classes of

proteins, while Biologically treated surfaces are designed

to interact specifically with a single target proteins


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The array is then inserted into the ProteinChip Reader

The ProteinChip Reader is a Laser Desorption/Ionization TOF - MS

Pulsed UV

Nitrogen

Laser source

When

laser is

activated

The sample becomes

irradiated, desorption and

ionization proceeds toliberate aseous ions

These gaseous ions enter the TOF-

MS region, which measures the

mass/charge of each protein based

on its velocity through an ion

chamber


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A) Detected proteins are displayed as a series of peaks showing relative

abundance of the detected proteins versus their MWs.

Spectra View

B) To identify differences between the detectd prtoeins, a software has beendeveloped to generate a simulated 1D gel electrophoresis

Gel View

C) Based on the spectra view, a map view will be also generated for better

identification

Map View


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Protein mapping for a certain disease

By using different chemically surface-treated arrays for the same sample.

Each surface will retain different groups of proteins depending on their

physiochemical properties as well as the pH of the sample.


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The end-result of a SELDI-TOF-MS analysis is a list of the

MWs of the proteins whose relative abundance differ

significantly between 2 or more samples.


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The identity of the peak masses used in the tree analysis pattern is

not necessary for making a diagnosis.

The only requirement for this classification system to make an

accurate diagnosis is that the biomarkers be reproducibly detected by

SELDI and accurately selected by the classifier.

However, because knowing their exact identities will be essential

for understanding what biological roles of these peptide/proteins may

have in the cancer, efforts are under way to purify, identify, and

characterize these protein/peptide biomarkers.

(European Urology 47 (2005) 456462)


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The ability to simultaneously test forThe ability to simultaneously test for

multiple protein changes by themultiple protein changes by the

ProteinChip SELDI system increases theProteinChip SELDI system increases the

diagnostic sensitivity, and withdiagnostic sensitivity, and with

Biomarker Pattern Software, has theBiomarker Pattern Software, has the

potential to improve the Early diagnosispotential to improve the Early diagnosis

of Prostate Cancer.of Prostate Cancer.


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Ahmad Roushdy-Prostate Cancer Educational Seminar