Bcl-10 Mediates Aberrant NF-Bcl-10 Mediates Aberrant NF-B B Activity in Hepatocellular Activity in Hepatocellular

CarcinomasCarcinomas

Nathan Wilds

Summer 2004

Carcinomas of the liver and hepatic bile duct are 5th most common GI malignancies and 3rd most lethal neoplasm of GI tract.

In the midsouth an increase in HCCs is anticipated due to an increase in Hepatitis B and C infections.

NF-B is directly involved in normal immune and inflammatory responses, cell proliferation, differentiation, apoptosis, and oncogenesis.

NF-B is constitutively activated in murine and human HCCs.

IntroductionIntroduction

Identify crucial upstream and downstream components of the NF-B Pathway in murine

HCCs derived from bitransgenic animals. These animals are a widely used model of

liver carcinogenesis.

What is the mechanism of NF-B constitutive activation in cancer cells???

IKK complex

IB

NF-B

IBpp

IB UbUb

UbUb

Ub

UbUb

UbUb

Ub

pp

IB UbUb

UbUb

Ub

UbUb

UbUb

Ub

pp

NF-B

NF-B

NF-B

Degradation(26S proteosome)

Nuclear translocation

Canonical pathway of NF-kB Activation

Cytosol

Gene Array Shows Gene Expression Increasing Gene Array Shows Gene Expression Increasing From Surrounding Liver to Tumor.From Surrounding Liver to Tumor.

Transforming growth factor α Transforming growth factor β1 Cytochrome P450 (several variances) B-cell leukemialymphoma 10 (Bcl-10) Myeloid cell leukemia sequences Glucokinase (Gck) Deoxyribonuclease II alpha (DNase2a) Procollagen, type IV, 1 Carboxylesterase 3 (Ces3) Glutathione transferase

Bcl-10IKK complex

IB

NF-B

IBpp

IB UbUb

UbUb

Ub

UbUb

UbUb

Ub

pp

IB UbUb

UbUb

Ub

UbUb

UbUb

Ub

pp

NF-B

UbUb

UbUb

UbUb

Ub

NF-B

NF-B

Degradation(26S proteosome)

Nuclear translocation

Role of Bcl-10 in the NF-B pathway.

K562 WEHI t1 t2 t3 t4 t5 ma3 ma2 ma1 wt3 wt2 wt1

K562 WEHI t6 t7 t8 t4 t5 ma3 ma2 ma1 wt3 wt2 wt1

Bcl-10 is Over Expressed in Tumors When Compared to Dysplastic or Wild-Type Livers.

IB: Bcl-10

IB: Bcl-10

SL T SL T

Bcl-10 Expression in Bitransgenic Mice Comparing Surrounding Liver and Tumor Samples

IB Bcl-10

PCR Bcl-10

SL T SL T SL T SL T

IP IKK-γ + + +

223 T SL

IKK-γ

IB: Ubiquitan

IKK-γ is Ubiquitinated in Tumor, but Not in Surrounding Liver.

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5ng C IKK

50ng C IKK

Regulation of Regulation of FF--B ActivityB Activity

ConclusionsConclusions

Bcl-10 is overexpressed in tumors relative to surrounding livers as well as dysplastic and wt tumors,

Bcl10 is involved in the uibiquitination of IKK- in tumor samples,

IKK regulates NF-B activity in HCCs. Future experiments will determine whether Bcl-10

is involved in NF-B signaling in malignant hepatocytes. email

Acknowledgements Acknowledgements

The University of Tennessee Health Science Center, Dept of Pharmacology

ASPET Dr. Marcello Arsura and all the post-docs in his

laboratory; Drs. Swayamjot Kaur, Venkatramen Manickam, and Fang Wang, for all their answers to my “does this look right?” and “what in the world is this?” questions.

Questions???Questions???