cancer and immunity - the next frontier in cancer treatment

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CANCER AND IMMUNITY - THE NEXT FRONTIER IN CANCER TREATMENT

Zheng Cui, MD/PhD

Section of Tumor BiologyDepartment of PathologyWake Forest University

School of MedicineWinston-Salem, NC, USATelephone: 336-716-6185

Email: zhengcui@wfubmc.edu

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Acknowledgement

This presentation is made possible by:

Gailyn Waldron and Threshold, Inc.

Barbara Shook and the Barbara Ingalls Shook Foundation

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Current cancer therapies:

SurgeriesRemove cancer

at early stage

ChemoKill growing cells

systemically

RadiationKill live cells

locally

ImmunotherapiesRepair a weak/bad

immune system

Targeted therapies:Herceptin, Gleevec

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Cancer Stats:

Worldwide

~6,000,000,000

~6,000,000

~100/100K

Population:

Yearly cancer death:

Cancer mortality rate:(age-adjusted)

The US

300,000,000

600,000

~200/100K

US/W

1/20

1/10

2-fold

1950 2004

Heart disease

Cancer Death Rate

Mor

talit

y ra

te

(per

100

k po

pula

tion)

200

400

600CDC data

The outlook of cancer treatment is not so good!

>1600 cancer deaths a day in the US!

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May 8th, 2006

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May 8th, 2006

The second most blogged news story in May, 2006

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The most blogged news story in May: Britney Spears!

8Since then, she continues to make news….

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Smoking

General population Smokers

Lung cancer rate

0.08% 8%

Why don’t most smokers have lung cancer in the face of intense carcinogen exposure?

10

Cell Damage

Cell Damage

DNA repairClearance of cancer cells

Younger and healthier Older

Hostprotection

Hostprotection

Cause of cancer: cell damage and aging

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Modeling cancer

in animals

Understanding Cancer

mechanisms

Finding Molecular

targets

TestingTargets

Developinghuman therapy

Pathway #1: why do we get cancer

Pathway #2: why don’t we get cancer

FindingCancer-

ResistantHumans

Developinghuman therapy

Pathways to cancer treatment

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Modeling Cancers in mice

Spontaneous tumors at old age: 81% of laboratory mice have cancers at their natural deathbut often not aggressive

Carcinogen-induced cancersTakes months if not year

Genetically engineered tumorsTakes months if not year and often not malignant

Transplantable xenograft-human tumor cell linesOften not showing malignant properties

Transplantable mouse cancer cell linesToo aggressive, too lethal, too rapidS180, EL4, L5178, L1210, J774, LL2, MethA etc.

Aggressiveness

Survival time

Can

cer

type

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CR WT

CR

Days After S180 Injections

WT WT WT WT WT

Bod

y W

eigh

t in

Gra

ms

0

10

20

30

40

1 9 17 25 33 41 49 57

Completely unexpected

No exception

Serendipitous discovery of a cancer-resistant mouse

CR=cancer-resistantWT=cancer-sensitive

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Survival after cancer challenge is based on inheritance: it is all in the DNA

SR WT24 4037%

M 9 18F 15 22

15Finally, they are available free to research community!

From a single mouse to a great legacy!

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Cancer cells are specifically killed by white cells that formed “rosettes”

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Cancer cell killing is dependent on cell-cell contact.

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Natural killer cells form rosettes and aggregates with tumor cells

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The surface of cancer cell is damaged before dying

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Presenceof pathogens

Innate immunity:Natural Killer cells (NK)

Macrophages (MΦ)Neutrophils (PMN)

Complements(Within hours)

Adaptive Immunity:B cells (antibodies)

T cells (CTL)Dendritic cells (DC)

Macrophages(Weeks)

An overview of two arms of immune system

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Cell aggregation

White cells are tracking down cancer cells

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Mixed pop-rosettes

Cancer cells are ruptured by white cells

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Mixed pop

Cancer cells are ruptured by white cells

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Pmn-apop

A much larger cancer cell killed by a small white cell (neutrophil)

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0

20

40

60

80

100

120

140

160

180

200

0 2 4 6 8 10 12 14 16 18 20Days After Cancer Establishment

Tu

mo

r V

olu

me

rela

tive

to

Co

ntr

ols

(%

)

WT-ATSR/CR-AT

AT

0

20

40

60

80

100

0 4 8 12 16 20 24 28 32 36 40 44

Days Post-Tumor Injection

Su

rviv

al (

%)

WT-AT, n=5SR-AT, n=7

AT (day 4)

0

500

1000

1500

2000

2500

1 3 5 7 9 11 13 15 17

Days after adoptive transfer of leukocytes

Tu

mo

r V

olu

me

(m

m3

)

SR/CR, n=14WT, n=8

AT

SR AT 1-day 8-day 12-day 18-day 23-day

Cure established cancers in WT mice by systemic WBC therapy

Still alive after 18 months

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n=10

Cure of mouse prostate cancer by white cell infusion

0

20

40

60

80

100

0 1 2 3 4 5 6 7 8 9 10 11 12

Age (Months)

Su

rviv

al %

No AT

SR/CR AT

White cell infusion

Cancer cell challenges

n=7

Dr. Yong ChenCancer Biology

WFUSM

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WT PTEN-KO PTEN-KO + SR

Normal Cancer Scars

It is a permanent, complete cure of cancer!

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Genetically defined

No need for further manipulation

Involves the innate immunity that has been mostly ignored

Highly effective: survival of million times more lethal doses

No side effect

Kill different cancers

Transferable to treat established cancers in ordinary mice

The innate immunity of cancer-resistant mice can cure cancer

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Why do we have natural protection against cancers:Humans and other large, long-living animals must have

exceptional natural resistance and immunity against malignancy in order to survive beyond reproductive ages

Why don’t normal mice have meaningful resistance or immunity against malignancy?

Mouse Human Difference

Body size 25 g 75,000 g 3000 x

Lifespan 2.5 (<1) y 75 y 30 x

Pre-reproduction 8 w 800 w 100 x

% with ca at death 81% 25% 3.2 x

Cancer Surveillance ± +++++

Cancer-resistance and humans

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Mice in the wild have a tough life and don’t live long enough to get cancer.Therefore, there was no natural selection for resistance against cancers.

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If humans do have cancer-resistance, can we measure it?

Can we inject cancer cells into humans to find out?

Probably not!?

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Cancer Cells White blood cells

% killed

70 30 40 / 70 = 57.3% Killed

Incubation

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Manual test of cancer cell killing activity:How well the white cells can kill cancer cells in test tubes

Control: cancer cells without white cells(100% survival)

Cancer cells with white cells (Ratio at 50:1)(some survival)

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21 42 63 84 105

Hela + non-killing control cells: 1:20

Automated real-time recording of cancer cells killed by WBC

Hela control

Hela + WBC: 1:20

Time in hTime point of manual assays

Addition of effector cells

1

3

2

1

3

2

=0% kill

=30% kill

=50% kill

Plating target cells

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1

2

3

4

5

6

7

Killing inTest tubes

-+

+

+--

-

Resistant/Survival after challengeLitter mates

Identifying cancer-resistant mice without a cancer cell challenge

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12.5

25.0

37.5

50.0

75.0

62.5

87.5

In v

itro

canc

er k

ill a

ctiv

ity

(tar

get

cells

kill

ed %

)

100.0

0WT Mice SR mice

Test-tube cancer resistance results using cancer-resistant and non-resistant mice

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12.5

25.0

37.5

50.0

75.0

62.5

87.5In

vitr

o ca

ncer

kill

act

ivity

(S

180

cells

kill

ed %

)

100.0

0WT Mice Young

SR miceOld

SR miceOld SR mice cancer cells

S180 cells

Mouse cancer-resistance by age

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12.5

25.0

37.5

50.0

75.0

62.5

87.5

In v

itro

canc

er k

ill a

ctiv

ity

(tar

get

cells

kill

ed %

)100.0

0WT Mice Humans

>50y, CaSR mice Humans

>50yHumans

<50y

Hela cells

Human cancer-resistance by age

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White cells that don’t kill cancer cells White cells that kill cancer cells

Automated recording of cancer cell kill

40Cancer patientNo rosettes

Hela cellsHuman WBC

Mouse S180 cellsSR mouse WBC

Rosette formation leading to cancer cell kill

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Surveillance by human white cells

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Cancer cell killed by a smart bomb (white cell)

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Stability of cancer-killing activity in human WBC

100

80

60

40

20

02 4 6 8 10 12 14 16

% o

f ca

nce

r ce

lls k

illed

Time span in weeks

Stress

Recovery in 3 days

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Stability of cancer-killing activity in human WBC

100

80

60

40

20

02 4 6 8 10 12 14 16

% o

f ca

nce

r ce

lls k

illed

Time span in weeks

Stress

Recovery in 3 months

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Seasonality of CKA activity?

100

80

60

40

20

0Aug Sep Oct Nov Dec Jan Feb Mar

% o

f ca

nce

r ce

lls k

illed

Northern Hemisphere:Shorter daylightLower intensity of sunlight radiationLower temperatureVitamin D deficiency

Higher mortality rate in elderlyInfluenza seasonLower immune responsesSevere mood swing (SAD)

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Injecting human subjects (Inmates and ca patients) with live cancer cells

Ethical and legal problems

Elected to the president of AACR in 1968

Chester Southam:

Healthy humans were resistant to cancer cells.Cancer patients lost cancer resistance while retained antimicrobeial resistance.

Science 25 January 1957 125: 158-160

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Possible effects of aging and stress on CKA of human WBC

75%

25%

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Anticancer protection can be lost due to:

1. Genetics

2. Aging

3. Stress

4. Seasonal changes

5. Too many cancer cells (increased carcinogenesis)

6. Too few immune cells (immune suppression)

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A new cancer treatment concept:

To replace a weak/bad immune system with a validated, functional one rather than to repair it

50White cells

CKA screening

Healthy volunteers

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Donor selection: CKA, Availability, ABO, Virus status

Patient selection: reasonable condition

Dose escalation

Safety control: GVHD

Routes of delivery: systemic, local

Combination with existing therapies

The new cancer treatment concept

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Uniqueness of this treatment:

No drug involved

Technology- and knowledge-based

Minimal side-effect is expected

Involves innate immunity (macrophages and neutrophils)but not adaptive immunity (T cells)

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*n=14

Adoptive Transfer in different age groups

0

20

40

60

80

100

0 20 40 60 80 100 120

Days after S180

Su

rviv

al

Pe

rce

nta

ge

Young to Young (n=16)

Young to Old (n=15)

Old to Young (n=16)

Old to Old (n=16)

Old cells Young cells

100

80

60

40

20

0

Old

re

cipi

ents

Old

re

cipi

ents

You

ng

reci

pien

ts

You

ng

reci

pien

ts

Old cells Young cells

100

80

60

40

20

0

Old

re

cipi

ents

Old

re

cipi

ents

You

ng

reci

pien

ts

You

ng

reci

pien

ts

Young=3-6 months

Old=22-26 months

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0

20

40

60

80

100

Per

cen

t S

urv

ival

Control Sex

Mismatch

MHC

Mismatch

Sex+MHC

Mismatch

Mismatched Adoptive Transfer in Mice

Male recipients

Female recipients

n=12 in each group

10083.3

58.341.7

0

20

40

60

80

100

Pe

rcen

t S

urv

ival

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Why hasn't this treatment for cancer been tested yet?Differences with conventional funding philosophy

No mechanism: rational design vs empirical approach. (Pathways of development)

A radical departure from textbook: innate immunity vs adaptive immunity

Too good to be true

Not from a well-known establishment

Worsening funding environment

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$10 million is needed for:

Clinical trials in humans for different cancers

Clinical trials in dogs

Developing techniques for long-term storage of cancer-killing white cells

Refinement of CKA assay: automation

Funding requirements to treat human cancer patients

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Cancer and Immunity: the Next Frontier in Cancer Treatment

The Promise

No more disfiguring surgeryNo more toxic chemotherapy

No more damaging radiation therapiesNo more cancer recurrence

Permanent cures for cancer using the immune system

We can cure cancer using what we have learned from cancer-resistant mice

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Funding:CRINCIWFUCharlotte Geyer

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Many thanks again to:

Gailyn Waldron and Threshold, Inc.

Barbara Shook and the Barbara Ingalls Shook Foundation

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