1. Possible Loci Linked to Prostate Cancer
By Angela Marks
Biochemistry/Molecular Biology Seminar

2. The Facts about Prostate Cancer
Most common malignancy among U.S. men
Estimated 179,300 new cases in 1999
1 in 5 lifetime probability of diagnosis in U.S. men
African Americans have 34% higher incidence rate and 2 times higher mortality rate than white Americans
Asian men have lowest incidence rate
Estimated 37,000 deaths in 1999 in U.S.
20,000 men under 65 years
0.1% of cases are diagnosed under 40
9% of whites and 10% of blacks develop pc in lifetime
PC in 15% of US men
Works out to about 1 new case every 3 minutes
Incidence rate increased 141.8% between 1973 and 1994.
Asians lowest rate among blacks and whites.
When asians move to America there risk increases
Life lost to pc every 13 minutes
2nd leading cause of cancer death 1st is lung cancer
13% of male cancer deaths.
talk about this later? Yes during the factors slide. Differences between whites and blacks may be due to screening, environmental and biological factors.

3. The Prostate Gland Male sex gland Size of a walnut
Helps control urine flow
Produces fluid component of semen
Produces Prostate Specific Antigen (PSA) and Acid Phosphatase
Located in lower pelvis just below the bladder and in front of the rectum
Surrounds the urethra
prostate 4cm in diameter at broadest point
PSA is good indicator of activity of prostate
PSA tests are used to diagnose PC along with a physical examination.

4. Four Areas of the Prostate
Prostate cancer is most likely to occur in the peripheral zone.
also known to occur in the central zone
Surrounding the prostate is the prostate capsule
When pc remains within this capsule, it is considered localized and treatable with surgery.
Once the cancer punctures the capsule and spreads outside, treatment is limited. This tumor is then labeled metastatic.
Transition Zone
Peripheral Zone
Anterior Zone
Central Zone

5. Factors Increasing Risk of Prostate Cancer
Age
Lifestyle
Hormones
Race
Genetics
Although no one is sure what causes pc, thesefactors seem to be asssociated with PC. Age, lifestyle hormones, and race all seem to alter the genetic make-up of prostate cells to cause PC
*Age as age increases, the risk of pc also increases
only 25% of cases diagnosed under 65.
* lifestyle=Diet, alcohol, smoking
Foods high in fat especially red meat are associated with increased risk of pc.
evidence is weak.... Fat may increase the levels of sex hormones increase risk of pc
Unsat fatty acids may have role in regulating Androgen action in target cells by altering 5alpha reductase activity.
Linolenic acid in cell memb. May increase formation of free radicals (alter DNA)
Good food= lycopene in tomatoes aids by protecting against oxidation
soy proteins and fiber may reduce risk
*Hormones Hormone-dependent PC.A
Altered hormone metabolism and Androgen receptors
Testosterone levels
*Race As discussed previously,
African Am men have a higher rate of PC while white men are intermediate and asian men have the lowest rate of PC. This trend has been attributed to lifestyle (diet), hormones, and genetics.Af american men also have higher levels of testosterone. Be able to explain why testosterone increases risk.
I am going to concentrate on the genetics of prostate cancer
The germline heredity which cause pc

6. Genetic mutations in Prostate Cancer?
Germline mutations
Methylation changes
Loss of GSTp expression
Androgen receptor - short tandem repeats (Xq11-12)
Chromosome 16q loss
These are only suggested areas of mutation. Studies have only found correlations. There is no solid proof. In almost all of these cases there is strong controversy over the association locus’ association with PC.
I will be concentrating on possible germline mutations
*Methylation changes = studies show tumor cells have distinctive methylation points. Found CpG islands within ORF of growth regulatory genes.J
*Loss of GSTpi expression= can’t scavenge for free radicals. Maybe meth mut
*AR
*(C) 16q loss =Altered E-cad expression *(C) 8p loss= shown in preCan cells
*Loss of KAI1 (11p) region may contain metastasis suppressor gene. When deletion/mutation occurs, metastasis proceeds. (4 hydrophobic/TM domains and one large extracellular hydrophilic domain with 3 potential N-glycosylation sites) Encodes a member of a structurally distinct family of leukocyte surface glycoproteins
Negatively regulates myc oncoprotein activity thus serving as a tumor suppressor. (Eagle 1995, )
Mutation = nonmetastatic tumor turning into a metastatic tumor
KAI1 prtn is leukocyte surface glycoprtn (fn unknown) but their memb localization and extensive glycosylation suggests they fn in cell-cell interactions and cell-extracellular matrix interactions. W
*p53 inactivation (17p)= G:C to A:T transitions, these mutations may be predictive of metastasis
PTEN mutation (10q23)
p53 inactivation (17p)

7. Early event in development of prostate cancer
CpG islands within promoter regions and open reading frames of growth regulatory genes
Small polymorphic CAG repeats (microsatellites) associated with transactivation activity
Inverse relationship between CAG repeats and prostate cancer
Glutathione S transferase -pi (GSTp) scavenges free radicals
Loss may be caused by methylation
GSTp absent in almost every prostate tumor
GSTp may be only thing stopping prostate cancer
16q is sight of tumor suppressor gene, E-cadherin
Loss of E-cad increases disease progression

8. PTEN phosphatase functions as a tumor suppressor by negatively regulating cell interactions
Acts as a gate to regulate the movement of growth-regulating signals
G:C to A:T transition mutation
Inactivation of p53 results in loss of DNA repair

9. Possible Germline Mutations
Hereditary Prostate Cancer 1 gene (HPC1) on chromosome 1q24-q25
Predisposing locus for early-onset prostate cancer (PCAP) on 1q42.2-q43
Hereditary prostate cancer locus (HPCX) on Xq27-q28
Rare PC-Brain Cancer Susceptibility locus (CAPB) on 1q36
Studies suggest that 5- 10% of PC is heredited through an autosomal dominant allele
Responsible for 40% of early onset cases
The penetrance of this hereditary PC is high - 88% at age 85.
HPC1 controversial
loci not determined and mechanism not known.
may or may not be a tumor suppressor gene.

10. Future Research Comparative Genomic Hybridization (CGH)
Loss of Heterozygosity . (LOH)
Linkage Analysis
Genome search using CGH(comparative genomic hybidization), LOH (loss of heterozygosity), and targeted linkage analysis or genotyping(using semiautomatic ABI sequencer)
Looking for tumor suppressor gene often has STRs
Project seeks to 1. Perform CGH using DNA microdissected from paraffin-embedded blocks containing Prostate tumor from 3 individuals in each of four pedigrees. Tumor tissue is labeled with fluorecein (FITC) labeled ntds (nick translation) and normal tissue is labeled with Texas red (TRITC) labeled ntds. Equal amounts will be hybridized to see specific chromosomal regions in which the mutations fluouresce CGH screens for genetic changes, gains and losses, reveals characteristic patterns and imbalances. But not translocations or inversions or small deletions therefore must use LOH analysis.
2. Perfom LOH or allelic imbalance studies on the tumor DNA in order to corroborate and narrow the region identified by the CGH studies. Uses microsatellite markers on the regions specified by CGH.
Explain pictures; PCR with fluorescently labeled oligos on normal and tumor DNA. Gel electrophoresis using ABI 377 automated sequencer. Red is internal std. The different colors represent different PCR products. With coordination of colors and sizes up to nine alleles can be assayed at once. As bands pass the laser window of the computer, they are detected and their signal is sent to a computer for processing. Signal Peaks are then analyzed for allelic imbalance.
3. Fine map the genetic region thru targeted linkage analysis. Using more microsat. Markers and sequencing of more specific regions.
4.Then positional cloning and gene identification studies.
Pictures: and

11. Clone those genes to better understand function
Will expand on knowledge of non-hereditary causes of prostate cancer
Allow for more accurate diagnoses and better treatments

12. Genome-wide search for susceptibility loci

13. References Barry, R. et al. Grant proposal. Mayo Clinic. 1998.
Berthon, P. et al. Predisposing Gene for Early-Onset Prostate Cancer, Localized on Chromosome 1q Am J. Hum Genet 62: , 1998.
Capcure. The Association for the Cure of Cancer of the Prostate.
Dahiya, R., et al. High Frequency of Genetic Instability of Microsatellites in Human Prostatic Adenocarcinoma. Int J. Cancer 72: 762-7, 1997.
Gronberg, H., et al. Early Age at Diagnosis in Families Providing Evidence of Linkage to the Heredita Postate Cancer Locus (HPC1) on Chromosome 1. Cancer Research 57, , 11/1/97
Irvine, RA., et al. The CAG and GGC microsatellites of the androgen receptor gene are in linkage disequilibrium in men with prostate cancer. Cancer Research 1;55(9): , 1995.
Joslin Diabetes Center, DNA Core Facility. Microsatellites.
Kang, HY., et al. Cloning and Characterization of Human Prostate Coactivator ARA54, a Novel Protein that Associates with the Androgen Receptor. J Biol Chem 274(13): , 03/26/99.
Li, L., et al. PTEN, a putative protein tyrosine phosphatase gene mutated in human brain, breast, and prostate cancer. Science 275: , 1997.

14. References
Navone, NM, et al. p53 mutations in prostate cancer bone metastases suggest that selected p53 mutants in th eprimary site define foci with metastatic potential. J Urol 161(1):304-8, 1/99.
Pienta, K., Goodson, J., & Esper, P. Epidemiology of Prostate Cancer: Molecular and Environmental Clues.
Smith, J, et al. Major Susceptibility Locus for Prostate Cancer on Chromosome 1 Suggested by a Genome-Wide Search. Science 274: , 11/22/96.
Veterinary Genetics Laboratory, School of Veterinary Medicine University of California, Davis. Microsatellites /30.97
Wolf, G. University Hospital Charite Institute of Pathology /15/99
Xu, J., et al. Evidence for a prostate cancer susceptibility locus on the X chromosome. Nature Genet 20: , 1998.