Lecture 1

Question 1

A tumor or Neoplasm is

Answer 1

a group of cells which display unregulated proliferation

Question 2

Benign

Answer 2

Clustered in a single mass , not capable of indefinite growth and not able to invade healthy
surrounding tissue

Question 3

CANCER refers specifically to

Answer 3

MALIGNANT tumour

Question 4

Metastasis is the

Answer 4

ability of a malignant tumor to form 2o
tumors (metastases) at other sites in
the body. Small clusters of cancerous cells dislodge from the primary tumour to invade the
blood or lymphatic vessels and are carried to distant sites, take up residence and continue to
proliferate

Question 5

Majority of human tumours arise from

Answer 5

Epithelial tissue

Question 6

Carcinomas (80-90% cancers)

Answer 6

are of epithelial origin
eg skin, gut or epithelial lining of internal organs and glands)
Cancers of Breast, colon, prostate, lung, stomach, skin, oesophagus, liver, ovary, gallbladder and urinary bladder are
carcinomas.

Question 7

Non-epithelial cancers
Leukemia, Lymphoma and multiple
myeloma (9% of all cancers) are

Answer 7

malignant tumours of hematopoietic
cells derived from bone marrow (cells
of the immune system, including T and
B cells.

Question 8

Sarcoma (1% cancers)

Answer 8

arise from a variety
of mesenchymal cell types including
osteoblasts (bone-forming
cell)[Osteosarcoma], adipocyte (fat
cell)[Liposarcoma] and fibroblast
(connective tissue cell)[Fibrosarcoma].

Question 9

The 3rd group of nonepithelial
tumours arise from cells that

Answer 9

form
part of the central and peripheral
nervous systems. Includes gliomas,
glioblastomas, neuroblastomas,
medulloblastomas. Makes up 1.3%
of all diagnosed cancers, but 2.5%
of cancer deaths.

Question 10

Oncogenes are involved in

Answer 10

cell growth promoting
processes.

Question 11

• Tumor-suppressor genes allow

Answer 11

cancer cell survival when
they fail

Question 12

• Apoptosis

Answer 12

when faults-leads to abnormal cell survival

Question 13

Oncogenes are usually

Answer 13

“gain of function mutations”
generally dominant eg cMYC

Question 14

Tumor suppressor genes (TSGs) are usually

Answer 14

“loss of function mutations”
generally recessive eg Rb

Question 15

Mutation of both copies of a tumor suppressor gene
allows

Answer 15

dysregulated division/ excess proliferation.

Question 16

Is an activating mutation in a single oncogene sufficient to cause cancer

Answer 16

An activating mutation in a single oncogene is not sufficient
to cause cancer

Question 17

Oncogenes must collaborate with one another and with what to generate cancers?

Answer 17

Oncogenes must collaborate with one another and with
inactivation of Tumour Suppressors in order to generate
cancers

Question 18

In their normal state, TSGs prevents

Answer 18

cells from progressing
through the cell cycle inapproprately, functioning like
Brakes eg RB

Question 19

In precancerous and cancerous cells many what are seen?

Answer 19

• In precancerous and cancerous cells many chromosomal
  alterations are seen

Question 20

Functions of Proto-oncogenes

Answer 20

In general they encode elements of the cell’s signal
transduction network and parts of the cell cycle control
system
>100 proto-oncogenes known.
Highly conserved through evolution
* Growth Factors
* Growth Factor Receptors
* Signal Transduction Molecules
* Nuclear Proteins

Question 21

Proto oncogenes encode

Answer 21

Growth factors, growth factor receptors, signal transduction molecules and nuclear proteins

Question 22

Signal transduction molecules

Answer 22

A. Cytoplasmic membrane associates proteins - src (tyrosine kinase); ras (GTP- binding protein)
B. Soluble signal transduction proetins - raf (serine/threonine kinase)