class 2 (ch9; clinical manifestations of cancer)

Question 1

what is cancer?

Answer 1

cancer is a collection of more than 100 diffferent diseases, each caused by a specific and often unique accumulation of genetic and epigenetic alterations

Question 2

what is a tumor?

Answer 2

any swelling caused by inflammation, but now used to describe a new growth (Neoplasm)

Question 3

what are the two type of cancer?

Answer 3

Malignant or benign

Question 4

what are benign tumors?

Answer 4

well-differenciated cells and well organized stroma; surrounding capsule fo the CT

Question 5

what is a malignant tumor?

Answer 5

have more rapid growth rates and specific microscopic alterations, including loss of differentiation and absence of normal tissue organization. often have large darkly stained nuceli and mitotic cells are common

Question 6

anaplasia

Answer 6

loss of cellular differentiation

Question 7

pleomorphic

Answer 7

marked variability of size and shape

Question 8

metastasis

Answer 8

the ability ot spread; very dangerous in cancer cells

Question 9

carcinomas

Answer 9

cancer cells arising in the epithelial tissue

Question 10

Carcinoma in situ (CIS)

Answer 10

early stage growths are localized to the epitheium but have not penetrated the local basement membrane or invaded the surrounding stroma.

Question 11

where are CIS found?

Answer 11

cervix, skin, oral cavity, esophagus, and bronchus.

Question 12

how do we classify tumors?

Answer 12

immunohistochemical analysis and protein expression

Question 13

tumor markers?

Answer 13

substances produced by both benign and malignant cells that are either present in or on tumor cells or found in blood, spinal fluid, or urine.

Question 14

paraneoplastic syndrome

Answer 14

if the tumor marker itself has biologic activity, then it could cause symptoms.

Question 15

what does it mean when tumor markers are elevated?

Answer 15

ones that are high early in the course of common cancers remains a high priority beause the early detection of cancer often improves the Tx outcome.

Question 16

what are transformed cells?

Answer 16

cancer cells are described as transformed cells because they can be created from normal cells. (often have markedly decreased requirments for external growth factors).

Question 17

what is contact inhibition?

Answer 17

unlike normal cells cancers cells lack this and continue to crowd; eventually piling up on eachother.

Question 18

anchorage dependednt?

Answer 18

cancer cells continue to divide even when they are suspended in a soft agar gel. ( normal cells usually dont grow unless they are attached to something).

Question 19

what is the epidemilogic date about cancer?

Answer 19

each individual acquires a number of genetic “hits” or mutations over time. four-seven genetic hits are required over time for full blown cancer to occur.

Question 20

what is clonal proliferation?

Answer 20

progency can accumulate faster than nonmutent neighbors.

Question 21

what are oncogenes?

Answer 21

mutant genes that in their normal nonmutant state direct synthesis of proteins that positively regulate (accelerate) proliferation.

Question 22

tumor-supressor genes?

Answer 22

encode proteins that in their normal state negatively regulate proliferation. prevent cell mutation.

Question 23

what are the three types of DNA changes?

Answer 23

small DNA changes, large DNA changes, and epigenetic changes.

Question 24

what are point mutations?

Answer 24

small scale changes in DNA, the alteration of one or a few nucleotide base pairs.

Question 25

what are chromosome translocations?

Answer 25

they are large changes in chromosome structure in which a piece of one chromosome is translocated to another chromosome.

Question 26

what is copy number variation?

Answer 26

larger regions of DNA encompassing entire genes can be gained or lost. (during cancer it may amplify oncogenes or delete tumor supressor genes).

Question 27

what is gene amplification?

Answer 27

a type of chromosome structural abnormality bthat can activate oncogenes. they are the result of duplication of a region of a chromosome over and over again so that there may even be hundreds of copies present.

Question 28

retinoblastome (RB) gene?

Answer 28

one of the first discovered tumor supressor genes, normally strongly inhibits the cell division cycle.

Question 29

what is inactivated and activated in cancer?

Answer 29

oncogenes are activated and tumor suppressor genes are inactivated. (it takes 2 hits to inactivate).

Question 30

what is loss of heterozygosity?

Answer 30

for the fucntion of a tumor supressor to be lsot, both chromosomal copies (alleles) of the genes must be inactivated. so by just losing one you have LOH

Question 31

what is epigenetic silencing?

Answer 31

caused by reversible chemical modification (methyalon or acetylation) of histones and related chromatin components.

Question 32

what happens during epigenetic silencing?

Answer 32

whole regions fo chromosomes are normally shut off by silencing, so that the pattern of gene expression is different than that seen in other cells with the same genes.