TRAnslational research in Clinical Oncology (TRACO)

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TRAnslational research in Clinical Oncology
(TRACO)
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Program Director

• Terry W. Moody, Ph.D.
• [phone]
• FAX [phone]
• Bldg. 31, Rm. 4A48

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Organizing Committee

• Irwin Arias
• Terry Moody
• Lyuba Vartikovski
• Jonathan Wiest
• Farah Zia

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SYLLABUS

• DATE TOPIC SPEAKERS
• Sept. 10 Introduction, Lung Cancer Moody,
  Giaccone
• Sept. 17 NO CLASS
• Sept. 24 Ovarian Cancer, Prostate
  Cancer Annunziata, Gulley
• Oct. 1 Lymphoma, Topoisomerases
• Wilson, Pommier
• Oct. 11 HIV, TGF beta Maldarelli, Jakowlew

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SYLLABUS, continued

• DATE TOPIC SPEAKERS
• Oct. 15 Breast Cancer, Small Molecules
• Zia, Marugan
• Oct. 22 Tumor Imaging, Cancer Disparities Choy
  ke, Ambs
• Oct. 29 Cancer Stem Cells, Epidemiology
  Salomon, Caporaso
• Nov. 5 Radiation Oncology, Angiogenesis Campha
  usen, Zudaire
• Nov. 15 RNAi, Cancer Epigenetics Caplen, Verma

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SYLLABUS, continued

• DATE TOPIC SPEAKERS
• Nov. 20 Cervical Cancer, Case Report Schille
  r, Olaku
• Nov. 26 Inflammation, Lung Cancer Harris,
  Szabo
• Dec. 3 Genomics, Colon cancer Khan, Young
• Dec. 13 Nanotechnology, Pancreatic cancer
  Doborvatskaia, Hussain

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REGISTRATION

• The course is open to all interested personnel
  without charge. Registration is available at the
  NCI CCR Web site http//ccr.cancer.gov/careers/co
  urses/traco/registration/default.aspx

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CCR component

• Registrants can attend tumor boards, grand
  rounds, visit technology and/or core facilities.
  Please contact Dr. Moody, if interested to make
  appropriate reservations.

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COURSE CERTIFICATION

• Registrants can obtain a course certificate
  upon passing a computer graded final
  examination.

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Lung, colon, breast and prostate cancer account
for half of the U.S. cancer mortalities.

• TYPE INCIDENCE (MORTALITY)
• Lung 171,900 (157,200)
• Colon/Rectum 147,500 (57,100)
• Breast 211,300 (39,800)
• Prostate 220,900 (28,900)
• Others 582,500 (273,500)
• Total 1,334,100 (556,500)
• Jemal, Ward and Thun, Cancer Principles
  Practice of Oncology. Edited by DeVita, Hellman
  and Rosenberg. (2006), pp. 226-241

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Cancers which kill 10,000-30,000 U.S. patients
annually include

• Pancreatic cancer
• Non-Hodgkins Lymphoma
• Leukemia
• Stomach cancer
• Ovarian cancer
• Brain cancer
• Liver cancer
• Bladder cancer
• Esophageal cancer
• Kidney cancer

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Cancer risks include

• Alcohol
• Asbestos
• Diet
• Familial
• Hormones

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Cancer risks (continued)

• Obesity
• Ion Radiation
• Tobacco
• U.V. Radiation
• Viral

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Lung Cancer kills over 150,000 patients in the
U.S. annually.

• There are 45 Million current smokers and 45
  Million ex-smokers in the U.S.
• It is difficult to quit smoking due to nicotine
  addiction.

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Carcinogens which have been identified in
cigarette smoke include

• Polyaeromatic hydrocarbons (PAH),
• aza-arenes,
• 4(methylnitrosamino)-1-(3-pyridyl)-1-butanone
  (NNK),
• 1,3 butadiene,
• ethyl carbamate,
• ethylene oxide,
• nickel, chromium, cadmium,
• polonium, arsenic
• hydrazine

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The process by which unreactive carcinogen
converts to a form which binds DNA is known as
metabolic activation.

• Bay region diol epoxides are the principal PAH
  metabolites involved in DNA adduct formation.
  For Benzapyrene (BaP), BaP-7,8-diol-9,10-epoxide
  (BPDE) forms adducts with DNA leading to GCgtTA
  mutations in pulmonary DNA. The genes for p53
  and k-ras are frequently mutated.

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BENZ(a)Pyrene?The chemical structure of BaP is
shown.
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BaP is metabolized by enzymes to BPDE.

• BaP P450s Bap-7,8-oxide
  Epoxide hydrolaseBaP-7,8-diol
  P450sBPDE DNABPDE-N2-dG
  Acid hydrolysisBP-tetraolBoysen
  and Hecht, Mutation Res. 54317(2003).

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Carcinogens can be detoxified and excreted prior
to DNA damage.

• Cytochrome p450 enzymes catalyze addition
• of an oxygen to the carcinogen, increasing
• its water solubility.
• ? Phase 2 enzymes convert the oxygenated
• carcinogen to a form that is highly soluble in
• water, converting it to a form that can be
• excreted.

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DNA is mutated if the rate of carcinogen
activation exceeds the rate of carcinogen
detoxification and/or DNA repair.

• DNA adducts as well as intra- and
• interstrand DNA crosslinks are removed by
  nucleotide excision repair.

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P53, a tumor suppressor gene

• ?mediates the G1 to S-phase checkpoint of the
  cell cycle,
• ?drives programmed cell death or apoptosis after
  DNA damage,
• ?is increased along with p21 (cell cycle
  checkpoint) after DNA damage.
• ? Phosphorylated p53 induces expression of BAX
  (apoptosis), GADD45 (DNA repair) and
  thrombospondin (angiogenesis)

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P53 mutations are detected in most of the lung
cancer patients.

• G to T transversions occur at the CpG rich codons
  including 153-158 (exon 5), 248 and 249 (exon7)
  and 273 (exon 8) of the p53 gene. There is an
  excess of G to T transversions in smokers
  relative to non-smokers.

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P53 mutations
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Cell cycle phases.
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p53 mediates the G1 to S-phase checkpoint of the
cell cycle

• ?DNA damage increases p21 and p53.
• ?P53 drives programmed cell death or apoptosis
  after DNA damage

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Cell cycle enzymes
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Genotoxicity of tobacco smoke.

• ?After 10 years of chronic cigarette smoking,
  normal lung tissue can undergo hyperplasia and
  metaplasia.
• ?After 15 years, dysplasia can result.
• ?After 20 years, a carcinoma in situ can form.
• ?After 25 years, a malignant cancer can form.

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Carcinogenesis?Cancer progression occurs over a
period of decades.
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Normal lung?Carbon dioxide is exhaled from the
lung whereas oxygen is inhaled.
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Hyperplasia?After exposure to tobacco smoke,
hyperplasia can result.
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DysplasiaContinued exposure to tobacco smoke
leads to dysplasia.
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Adenoma?Continued exposure to carcinogens leads
to benign tumors such as adenomas.
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Adenocarcinoma?Chronic exposure to tobacco leads
to malignant tumors such as adenocarcinoma.
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Tumor formation ?Growth factors promote
carcinogenesis. Progression factors lead to
malignant tumors.
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Tumors?The primary cancer can undergo metastasis
to distant organs.

• Carcinoma
• Angiogenesis
• Migration, Invasion and Metastasis.

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Genetic abnormalities in lung cancer include

• Mutation of tumor suppressor genes such as p53
• Silencing of tumor suppressor genes such as p16,
  Rb
• Amplification of oncogenes such as
• c-myc, cyclin D1, EGF receptor, erbB-2

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Types of Lung Cancer.

• SCLC (small cell lung cancer)
• NSCLC
• adenocarcinoma
• large cell carcinoma
• squamous cell carcinoma

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SCLC or oat cell carcinoma

• Kills approximately 20,000 patients in the U.S.
  annually.
• Is a neuroendocrine tumor.
• Is responsive to chemo- and radiation therapy,
  but relapse frequently occurs. The median
  survival time is less than one year.

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SCLC Biopsy Specimen
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Neural enzymes, peptides and transmitters may be
stored in the dense core neurosecretory granules
associated with SCLC.
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Lung cancer symptoms?Cough?Chest
pain?Shortness of breath?Pneumonia or
bronchitis?Bloody sputum
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Lung cancer chest X-ray
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Lung cancer chest CT-scan
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Lung cancer bronchoscopy
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Staging of SCLC

• Physical examination
• Serum chemistries and whole blood cell counts
• CT scan of chest and upper abdomen
• FDG PET scan
• CT or MRI of the brain
• Bone marrow biopsy (optional)

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SCLC patient survival.Treatment SurvivalNone
lt 3 monthsSurgery 6.5 monthsRadiotherapy 10
monthsMurren et al., Cancer Principles and
Practice of Oncology (2001) pp 983-1018
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Combination Chemotherapy Active combinations
include cyclophosphamide, doxorubicin,
VP-16(CDE), C, doxorubicin, vincristine
(CAV),E, cisplatin (EP),VP-16, ifosfamide, P
(VIP), andI, carboplatin, VP-16 (ICE).
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SCLC relapse?Initially, SCLC often responds to
chemotherapy?After relapse, chemotherapy is
often ineffective.?Field effect

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SCLC metastasis ?Liver (27)?Bone
(41)?Adrenals (31)?Brain (14)?Lymph nodes,
mediastinal (80)

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SCLC carcinogenesis ?Is SCLC derived from
neuroendocrine Kulchitsky cells or stem
cells??Initiated by tobacco smoke carcinogens.

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SCLC cell lines.?Bone marrow aspirates were
obtained from patients and mononuclear cells
collected. ?Lymph node aspirates and other
solid tumors were mechanically dissociated and
cell suspensions obtained by mincing and passing
through 60 gauge steel mesh.?The cells were
cultured in a serum free medium containing
selenium, IGF-I and transferrin. SCLC cells
grew as suspension cultures.

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Numerous cell lines were isolated from SCLC
biopsy specimens

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SCLC cell lines?SCLC make their own autocrine
growth factors.?From 1982-4, NCI established 31
SCLC cell lines. Subcutaneous injection of each
of the cell lines into nude mice resulted in
tumor formation.?The classic SCLC cell lines had
high levels of Dopa decarboxylase (DDC2-657
unit/mg), Bombesin (BB0.2-22 pmol/mg) and neuron
Specific enolase (NSE1200-18000 ng/mg).Carney
et al., Cancer Res. 452913 (1985).

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SCLC cell lines.Over a 20 year period, NCI
established 113 SCLCand 110 NSCLC continuous
human cell lines. ?A subset of SCLC is variant
SCLC, which has low levels of DDC, BB and
NSE.Phelps et al., J. Cell Bioc. Supp.
2432(1996).
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Loss of heterozygosity in lung cancer occurs on
several genes.

• Gene locus Tumor suppressor gene
• 3p12 FHIT
• 11q12 p15, p16
• 13q14 Rb
• 17q13 p53

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p53.

• Mediates the G1 to S-phase checkpoint of the cell
  cycle.
• Drives programmed cell death or apoptosis after
  DNA damage.
• P53 is inactivated in over 90 of the SCLC
  patients.

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Rb mutations (truncations, deletions, nonsense
mutations and splicing abnormalities) occur in
many lung cancer patients.

• Usually the wild type allele is lost especially
  in SCLC. The Rb protein is absent or abnormal in
  90 of the SCLC patients.

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BCL2 is overexpressed in approximately 85 of the
SCLC tumors.

• BCL2 suppresses apoptosis and inhibits responses
  to chemotherapy and radiotherapy.
• Antisense-BCL2 therapeutic trials are being
  conducted (Genasense is an 18-mer phosphothioate
  oligonucleotide).

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MYC overexpression

• Myc is overexpressed in approximately 30 of the
  SCLC patients.
• Less heterodimers are formed with Max reducing
  differentiation and programmed cell death.

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Autocrine loops

• SCLC has high levels on the neuroendocrine
  peptide gastrin releasing peptide (GRP) and
  scatter factor (SCF).
• When secreted from SCLC cells, GRP and SCF bind
  to cell surface receptors BB2R and c-KIT
  respectively to stimulate proliferation.
• Chepeha et al., Cancer Principles and Practice
  of Oncology (2011) pp 781-798.

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LKB1 inactivation

• LKB1 is a serine/threonine kinase that is
  inactivated in appproximately 50 of the SCLC
  patients.
• LKB1 causes phosphorylation of AMP activated
  protein kinase (AMPK) resulting in tumor growth
  suppression.

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Tyrosine kinase receptors are mutated in several
diseases leading to increased cancer
proliferation.

• EGFR mutations occur in the activation loop,
  especially L858R and G719S.
• Tyrosine kinase inhibitors (gefitinib and
  erlotinib) have been developed for the EGFR.
• Paez et al., Science 3041497 (2004)

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CML patients are sensitive to the small molecule
TKI Gleevec.

• This restores blood counts in
• patients and delays disease progression.

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CML patients have a genetic abnormality on
chromosome 22 (Philadelphia chromosome).
?Segments of chromosome 9 and 22 are fused
resulting in the bcr-abl gene. ?The resulting
tyrosine kinase is constituitively active.
?Bcr-abl tyrosine kinase actvity is inhibited by
Gleevec.

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Translocation of Bcr/Abl. ?Chromosome 22
translocates with chromosome 9. Molecular
Biology of the Cell Alberts et al., 2001.
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Translocation of Bcr-Abl Genes?Translocated
chromosome 9 appears larger and translocated
chromosome 22 appears smaller Freebies for
Teachers D. Kerrigan.
9
9
(q)
Ph
(22q)
22
bcr
bcr-abl
abl
Fusion protein with tyrosine kinase activity
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In a Phase I Clinical Trial,GleevecTM was
effective orally at a daily dose of 300 mg or
greater.

• Dose limiting toxicities included nausea,
  vomiting, edema and rash. (Sawyers and Druker.
  Cancer J. Sci. Am. 1999563).

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In a Phase II Clinical Trial,GleevecTM restored
normal blood counts in 53 out of 54
chemotherapy-resistant CML patients.

• After a year on Gleevec, 51 of
• these patients were still doing well. (Druker et
  al. N. Engl. J. Med. 2001 344 1038.).
• . Over a 5 year period, 89 of the patients
  treated with Gleevec had progression-free
  survival (OHare et al., Clin. Cancer Res. 2011
  17 212).

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Gleevec mechanism of action ?Gleevec blocks the
ATP binding site. Molecular biology of the cell
Alberts et al., 2001.
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GLEEVEC RESISTANCE

• ?Over a 5 year period, 17 of the patients
  initially sensitive to Gleevec became resistant.
• ?BCR-ABL point mutations occurred such as T315I
  near the ATP binding site impairing Gleevec
  interactions
• ?New drugs such as ponatinib or DCC-2036 are
  being developed which bind with high affinity to
  mutated BCR-ABL

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PRACTICAL STEPS TO PREVENT CANCER

• ?Check your house for radon.
• ?Check your house for asbestos.
• ?Take precautions at your workplace.
• ?Check your community water system.
• ?Avoid breathing polluted air.
• ?Protect your skin.
• ?Dont breathe smoke.
• ?Exercise daily.

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PRACTICAL STEPS TO PREVENT CANCER (continued)

• ?Avoid pesticides.
• ?Eat fruits and vegetables.
• ?Reduce red-meat consumption.
• ?Eat fish.
• ?Minimize fried foods.
• ?Drink alcohol in moderation.
• ?Avoid unnecessary x-rays.
• ?Reduce infections.

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REFERENCES?Hanahan, D. and Weinberg, R.A.
Hallmarks of cancer The next generation. Cell
2011 144(5) 646-74. ?OHare, T., Deininger,
M.W.N., Elde, C.A., Clackson, T., and Druker,
B.J. Targeting the BCR-ABL signaling pathway in
therapy-resistant Philadelphia chromosome-positive
leukemia. Clin. Cancer Res. 2011
17(2)212-21.