Lecture 2a: Characteristics of Cancer Cells

Question 1

Main cause for cancer cells is _________

Answer 1

DNA Damage

Question 2

Sporadic Cancer

Answer 2

Cancer occurring without a specific cause (Most frequent)

Question 3

Inherited Cancer

Answer 3

Cancer, usually risk of cancer, passed down (Least frequent)

Question 4

________ is a critical factor in cancer development and progression. Is prevalent in many human cancer types.

Answer 4

Unrepaired DNA Damage/Inefficient DNA damage repair (DDR)

Question 5

Agents that can cause DNA Damage and cancer

Answer 5

-Inherited (Hereditary)
-Carcinogens (UV Radiation or Chemicals)
-Oncogenic Viruses (HPV)
-Lifestyle (Smoking)
-Abnormal Cell Division

Question 6

Normal cells + Mutations

Answer 6

Cancer-initiating cells

Question 7

Stem cell + Mutation

Answer 7

Cancer Stem Cells (CSC)

Question 8

Normal cells become cancerous after mutations accumulate in the genes that control ____________ and ___________.

Answer 8

Cellular Proliferation and Cell Cycle

Question 9

DNA copying errors: Random, unpredictable DNA “Mistakes account for __________% of mutations in cancers.

Answer 9

Over 60%

Question 10

It is estimated that approximately _________% of cancers can be prevented if people avoided these risk factors.

Answer 10

40%

Question 11

Cancer Stem Cells (Defintion)

Answer 11

Rare immortal cells within a tumor that can both self-renew by dividing and give rise to many cell types that constitute the tumor and can therefore form tumors.

Question 12

Clonal Evolution in Cancer (Definition)

Answer 12

All tumor cells derive from one cancer cell “A” through the process of clonal expansion, genetic diversification, and clonal selection

Question 13

Explanation: If a tumor is found to have neoplastic cells of both A and B types.

Answer 13

It must have had a multicellular origin.

Question 14

Neoplasia

Answer 14

Clonal disease that begins as one regenerative cell and leads to genetic derivatives.

Question 15

Monoclonal tumors

Answer 15

Only a single cell is transformed from normal to cancerous behavior to become the ancestor of the cells in a tumor.

Question 15

Polyclonal tumors

Answer 15

Multiple cells cross over the border from normalcy to malignancy to become the ancestors of several genetically distinct subpopulations of cells within a tumor mass.

Question 15

Characteristic “Signature”

Answer 15

Distinguishing feature of the affected cell from the surrounding population of karyotypically normal cells (Translocation)

Question 16

How to find see if cancer cells have a common progenitor

Answer 16

The same identical translocation will be present in all cancer cells within an arising tumor.

Question 17

B16 mouse melanoma (2 weeks following injection in tail vein)

Answer 17

B16 cells are trapped in the lung and grow into metastasis causing easy recognition due to its dark color.

Question 17

Liver metastasis from intestine

Answer 17

Portal vein that drains blood from the colon into the liver provides a route for metastasizing colon cancer cells to migrate directly to the liver.

Question 18

Morphological differences in normal cancer cells

Answer 18

-Large cytoplasm
-Single nucleus
-Single nucleolus
-Fine chromatin

Question 19

Breast cancer if left untreated often mestasizes to the ________

Answer 19

Brain

Question 20

Morphological differences in cancer cells

Answer 20

-Small cytoplasm
-Multiple nuclei
-Multiple and large nucleolus
-Coarse chromatin

Question 21

Characteristics of normal (Benign) cells

Answer 21

-Nuclear variation in size and shape is minimal
-Diploid
-Low mitotic count (normal mitosis)
-Retention of specialization
-Structural differentiation retained
-Organized
Functional differentiation usually.

Question 21

Characteristics of Cancer (Malignant) Cells

Answer 21

-Nuclear variation in size and shape minimal to marked, often variable
-Range of ploidy
- Low to high mitotic count, abnormal mitosis
-Loss of specialization
-Structural differentiation shows wide range of changes
-Not organized
-Functional differentiation often lost

Question 22

Loss of contact inhibition

Answer 22

An important mechanism to local invasion and metastasis

Question 23

Dedifferentiation

Answer 23

Reversal of differentiated cell to the phenotype of a less differentiated cell, such as its precursor.
(Cancer cells lose characteristics of a well specialized cells and tissue becoming primitive, unspecialized cells.)

Question 24

Dedifferentiation toward embryonic-like stemness

Answer 24

One critical aspect of the changes that occur as benign lesions transition to malignant ones is the progressive acquisition of the undifferentiated state through reactivation of key classic stem cell signaling pathways.

Question 25

Notable classic stem cell signaling pathways

Answer 25

Oct4, Sox2, Wnt, and Notch

Question 26

Telomere activation for telomeres maintenance

Answer 26

Critical for the development of replicative immortality. Cancer cells maintain the telomere length by telomerase reactivation for stabilizing telomere length.

Question 27

Benign Tumor

Answer 27

-Limited destructiveness
-Grows slow and has distinct borders
-Does not invade other organs

Question 28

Malignant

Answer 28

-Eventually kill the most
-Can grow fats and have irregular borders
-Can spread to other organs (Metastasize)

Question 29

Keyword: Tumor

Answer 29

Permanent circumscribed morbid swelling consisting of a new growth of tissue, without inflammation.

Question 30

Keyword: Neoplasm

Answer 30

A new and abnormal growth of tissue in the body one resulting from uncontrolled proliferation of cells of a benign or malignant tumor

Question 31

Keyword: Malignant

Answer 31

Potentially fatal: having the property of uncontrolled growth, with loss of differentiation, invasion and destruction of local tissue, and often metastasis to distant sites

Question 32

Keyword: Cancer

Answer 32

A malignant growth or tumor in different parts of the body that tends to spread indefinitely and to reproduce itself, as also to return after removal

Question 33

Adenoma

Answer 33

Pre-invasive growth, a tumor that is not cancer. Has yet to penetrate the basement membrane.